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BULLETIN  No.  36 


SAN  FRANCISCO.  MAY.  1905 


GOLD  DREDGING 


IN  CALIFORNIA 


ISSUED   BY 


THE  CALIFORNIA  STATE  MINING  BUREAU 


FERRY  BUILDING,  SAN  FRANCISCO 


LEWIS  E.  AUBURY 


State  Mineralogist 


W.  W.  SHANNON 


SACRAMENTO 

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1905 


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BULLETIN  No.  36 


SAN  FRANCISCO,  MAY,  1905 


GOLD  DREDGING 

IN  CALIFORNIA 


ISSUED  BY 


THE  CALIFORNIA  STATE  MINING  BUREAU 


FERRY  BUILDING,  SAN  FRANCISCO 


LEWIS  E.  AUBURY 


State  Mineralogist 


SACRAMENTO 

W.  W.  SHANNON       ...       -       SUPERINTENDENT  STATE  PRINTING 

1905 


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BULLETIN  No,  36 


SAN  FRANCISCa  MAY,  1905 


GOLD  DREDGING 


IN  CALIFORNIA 


ISSUED  BY 


THE  CALIFORNIA  STATE  MINING  BUREAU 

FERRY  BUILDING,  SAN  FRANCISCO 


LEWIS  E,  AUBURY 


State  Mineralogist 


SACRAMENTO 

W.  W.  SHANNON       .        .       .       .       SUPERINTENDENT  STATE  PRINTING 

1  905 


LETTER  OF  TRANSMITTAL. 


To  HoK.  George  C.  Pardee,  Governor  of  California,  and  the  Honorable 
Board  of  Trustees  of  the  State  Mining  Bureau: 

Gentlemen  :  I  have  the  honor  to  transmit  Bulletin  No.  36,  ' '  Gold 
Dredging  in  California."  The  issuance  of  this  Bulletin  has  been  con- 
templated for  some  time,  and  some  information  concerning  the  subject 
was  Qbtained  in  1902,  but  owing  to  the  rapid  changes  which  have 
affected  this  branch  of  the  gold  mining  industry,  and  the  difficulty 
met  with  in  securing  accurate  data  which  would  serve  to  illustrate  the 
actual  conditions  of  gold  dredging  in  this  State,  it  has  been  deemed 
best  to  delay  the  publication  of  the  report  until  the  present  time. 

The  items  of  costs  of  operation,  which  are  so  vital  to  a  publication  of 
this  nature,  have  l^een  extremely  difficult  to  obtain  from  many  of  the 
companies  engaged  in  dredging.  This  has  not  been  due  particularly  to 
any  intention  on  the  part  of  the  companies  to  withhold  the  information, 
but  to  the  fact  that  many  operators  have  not  until  recently  preserved  a 
detailed  record  of  expenditures; 

I  wish  to  here  extend  many  thanks  to  Col.  J.  E.  Doolittle  for  his 
valuable  assistance  in  the  preparation  of  this  Bulletin,  and  also  to  the 
many  operators  who  have  furnished  information  and  assistance  which 
have  made  this  publication  possible. 

I  also  wish  to  thank  Mr.  0.  W.  Jasper  of  Oroville,  Mr.  Howard  D. 
Smith,  and  Mr.  A.  H.  Ward,  who  rendered  assistance;  also  many 
others  whose  names  are  not  here  mentioned  and  who  have  aided  in  the 
work  by  furnishing  valual^le  information. 

Engaged  at  various  times  in  securing  data  for  this  report,  and  who 
were  employed  as  Field  Assistants,  were  Mr.  P.  C.  Dubois,  Mr.  John 
D.  McGillivray,  Mr.  William  Forstner,  and  Mr.  G.  Holmes,  to  whom  I 
wish  to  express  due  recognition  for  their  ser\nces. 
Very  truly, 

LEWIS  E.  AUBURY, 

State  Mineralogist. 

San  Francisco,  May  15,  1905. 


CONTENTS. 


HISTORY      ------- -        -        .         7 

AREA  OF  DREDGE  GRAVEL -        -       ...    14 

GEOLOGY     ----------------        16 

AGRICULTURE     -        -        - -------    17 

YIELD  FOR  1903         -        -        - -        -        19 

THE  DREDGE        -        -        -        -        -        -        -        -        -        -        -        -        -        -        -    19 

SCREENS,  SLUICES,  ETC.      -        -        - -        35 

CREW  OF  A  DREDGE  -------------    41 

WORKING  COSTS      --------------        42 

PROSPECTING  AND  EXAMINATION  OF  CONDITIONS  '-----    60 

OROVILLE  DISTRICT      ------ -        -        68 

YUBA  DISTRICT  --------- 88 

BEAR  RIVER  DISTRICT        ------------        9I 

FOLSOM  DISTRICT      --------------    92 

CALAVERAS  COUNTY  -        -        -        -        -        ^        -        -        -        -        -        -        98 

PLUMAS  COUNTY        --------------    98 

SHASTA  COUNTY     -        -  ------------        98 

TRINITY  COUNTY        -        -        -        - -        .        .        -        -  102 

SISKIYOU  COUNTY         -------------      105 

APPENDIX-CALIFORNIA  STATE  MINING  BUREAU  -        -        -        -        -111 

DREDGE  DATA         --------..---  /-oW^r 


LIST  OF  ILLUSTRATIONS. 


Page. 

No.    1.  Relief  map  of  California Frontispiece 

2.  Map  of  Oroville  dredging  lands Folder 

3.  An  "old  timer" 8 

4.  The  old  method  of  working  the  ground  below  Oroville }> 

5.  Treat's  old  workings  on  Feather  River 11 

6.  First  successful  dredge  in  California. 12 

7.  Marion  steam  shovel  dredge,  Oroville 13 

8.  Tailings  piles  after  dredging  . 18 

9.  Dredger  hull,  in  course  of  construction 20 

10.  Dredger  in  course  of  construction,  showing  steel  gauntry 21 

11.  Digger  end  of  ladder — latest  type  of  close-connected  buckets.    Bucyrus  type  22 

12.  Digger  end  of  ladder — latest  type  of  intermittent  buckets.     Risdon  type..-  23 

13.  Digger  starting  cut  on  top  of  ground. L 24 

14.  Bucket  line  in  operation -  24 

15.  Close-connected  buckets  (loaded),  Bucyrus  type 27 

16.  Close-connected  buckets,  5  cubic  feet  capacity 28 

17.  Open-connected  buckets,  5  cubic  feet  capacity,  Risdontype 2ft 

18.  Boston  and  Oroville  Company's  dredge,  showingspuds 31 

19.  Tailings  stacker,  belt  conveyor., 32 

20.  Tailings  stacker,  bucket  conveyor 33 

21.  Latest  bucket  stacking  ladder 34 

22.  Showing  sand  pump  working ^34 

23.-  Showing  revolving  screen 36 

24.  Gold-saving  tables — Hungarian  riffles  and  quicksilver 37 

25.  Gold-saving  tables — cocoa  matting  and  expanded  metal  riffles 39 

26.  Bucyrus  type  of  dredge,  with  close-connected  buckets,  shaking  screens,  belt 

conveyor,  and  spuds 43 

27.  Risdon  type  of  dredge,  with  open-connected   buckets,   revolving  screen. 

bucket  conveyor,  and  headlines , 45 

28.  Oroville  Gold  Dredging  and  Exploration  Company's  dredge,  "  Biggs  Xo.  2  "  .=)3 

29.  Keystone  drill  at  work  at  Oroville  to  prospect  for  values  and  determine 

character  of  gravel --  62 

30.  Typical  vertical  sections  of  borings  in  four  different  California  fields m 

31.  General  view  of  the  Oroville  dredging  district 68 

32.  General  view  of  the  Oroville  dredging  ground  on  Feather  River,  looking 

north 69 

;33.  Dredge  of  the  Feather  River  Exploration  Company,  Oroville.    Risdon  type  71 

34.  Front  end  of  Dipper  dredge,  Oroville 72 

35.  Stacker    end    of  dredge,   showing    height  of    tailings    piles.     Lava    Beds 

Dredging  Co.,  Oroville 72 

36.  Oroville  Gold  Dredging  Company's  dredge.  Marion  steam  shovel  type.       -  74 


6  LIST   OF   ILLUSTRATIONS. 

Page. 
No.  37.     Indiana  Gold  Dredging  and  Mining  Conipany'.s  dredges,  No.  1  anil  No.  2, 

Bucyrus  type 75 

38.  Indiana  Gold   Dredging  and   Mining  Company's  dredge,  Bucyrus  type, 

showing  close-connected  buckets 76 

39.  Kia  Ora  dredge,  Oroville.     Risdon  type 77 

40.  Cherokee  dredge,  Oroville.     Bucyrus  type - 7i) 

41.  Pennsylvania  Gold  Dredging  Company 80 

42.  Pennsylvania  Gold  Dredging  Company's  dredge,  Oroville.    Golden  State 

and   Miners'  Iron  Works,  builders . 81 

43.  El  Oro  Dredging  Company's  dredge,  Oroville.     Link  Dredge  Machine  Com- 

pany's type 82 

44.  Viloro  dredge,  Oroville.     Latest  type  Bucyrus  dredge . .  _  83 

45.  Boston  and  Oroville  Dredging  Company's  dredge,  Oroville.     Risdon  type__  84 

46.  Boston  and  Oroville  Dredging  Company's  dredge,  "Continental."  Bucyrus 

type  as  remodeled 85 

47.  California  No.  3,  Oroville,  built  by  the  Marion  Steam  Shovel  Company 86 

48.  Marigold  No.  1,  Marigold  Dredging  Company,  near  Oroville 87 

49.  Front  view  of  the  Marigold  Dredging  Company's  dredge,  near  Oroville. -_  87 

50.  Stacker  end  of  Marigold  Dredging  Company's  dredge 89 

51.  Yuba  Consolidated  Gold  Fields  dredges,  each  of  6  cubic  feet  bucket  capacity. 

Bucyrus  type 89 

52.  Yuba  Consolidated  Gold  Fields  dredges,  each  of  6  cubic  feet  bucket  capacity. 

B  ucyrus  type 90 

53.  Ashburton    Mining  Company's   dredge,   at  Folsom,  Sacramento  County. 

Buckets  7^  cubic  feet  capacity 94 

54.  El  Dorado  No.  1,  Folsom  field.    Latest  type  of  Risdon  boat 95 

55.  Dredge  of  the  Colorado-Pacific  Gold  Dredging  Company,  Folsom 96 

66.     Syndicate  Mining  Company's  dredge,  Folsom.     Bucyrus  type 97 

57.  The  bedrock  of  the  Sacramento  River  at  the  mouth  of  Middle  Creek,  above 

Redding 99 

58.  Current  breakers  and  caissons  of  the  Huron  Submarine  Mining  and  Con- 

struction Company,  at  Redding ---  101 

59.  Huron  Submarine  Mining  and  Construction  Company's  caisson  dredge, 

above  Redding  -. ' 101 

60.  Galvin  Gold  Dredging  Company  of  Weaverville,  Trinity  County 102 

61.  Galvin  Gold  Dredging  Company's  dredge.  Trinity  County,  showing  char- 

acter of  gravel  ..-  103 

62.  Poker  Bar  dredge,  Trinity  County 104 

63.  Dredge  of  the  Yreka  Creek  Gold  Dredging  and  Mining  Company,  Siskiyou 

County ----■'- 106 

64.  Consolidated  Mining  and  Dredging  Company's  dredge  and  caisson 107 

65.  Ferry  Building,  San  Francisco HO 

66.  Mineral  Museum,  State  Mining  Bureau --.     113 

67.  Library  and  Free  Reading-Room,  State  Mining  Bureau 115 

68.  Laboratory,  State  Mining  Bureau 117 

69.  Map  of  field  of  operations  in  Folsom  District,  showing  locations  of  dredg- 

ing companies Folder 

70.  "Dredge  Data" Folder 


GOLD  DREDGING  IN  CALIFORNIA. 


:.  DOOLiTTLE,  e.m:. 


HISTORY. 


It  is  popularly  supposed  that  mining  for  gold  with  dredges  is  an 
industry  which  has  grown  up  within  the  last  decade,  and  that  it  was 
a  success  almost  from  the  beginning.  This  is  not  true.  There  are 
bleaching  skeletons  of  dredges  scattered  over  California  and  New 
Zealand,  some  of  which  were  built  nearly  half  a  century  ago.  There 
was  a  dredge  near  Oroville,  on  the  Feather  River,  in  the  fifties.  It  is 
over  forty  years  since  dredging  was  first  tried  in  New  Zealand. 
Spasmodic  attempts  were  made  in  this  direction  on  the  Pacific  Coast 
and  in  New  Zealand  from  that  time  on.  These  efforts,  futile  as  they 
were,  so  far  as  giving  dividends  to  shareholders  go,  were  of  great  value 
to  the  miner  and  mining  engineer  of  to-day.  These  failures  were  their 
warnings. 

As  a  result,  this  class  of  mining,  if  properly  directed,  is  now  as  safe 
as  any,  provided  that  skilled  investigators  direct  the  investment  and 
use  of  capital,  and  see  that  it  is  only  invested  where  conditions  permit 
of  successful  work. 

Any  one  investigating  the  processes  at  Oroville  or  Folsom,  or  in 
New  Zealand,  where  conditions  are  known  by  actual  practice,  will  find 
that  the  difficulties  have  been  largely  overcome  because  the  conditions 
have  been  studied  by  skilled  men  at  large  expense,  and  met  with  appli- 
ances fitted  for  the  local  needs,  not  only  as  to  the  digging  of  the  ground, 
but  also  as  to  the  saving  of  the  gold. 

But  under  other  conditions,  in  other  districts,  the  dredges  so  suc- 
cessful at  Oroville  or  Fol'^om,  or  in  New  Zealand,  would  be  failures  as 
to  some  of  their  parts.  To  explain:  At  Oroville,  the  gravel  is  loose, 
free  from  clay.  There  are  no  large  bowlders,  the  bedrock  is  soft,  the 
gold  is  fine  and  it  easily  amalgamates.  Along  the  streams  in  the 
mountains  of  California  the  bowlders  are  larger,  the  bedrock  harder, 
and  in  places  in  Idaho  and  Colorado  the  gold  will  not  amalgamate 
owing  to  the  presence  of  arsenic.  Then  there  are  many  other  condi- 
tions that  differ  in  other  places.  Some  of  these  difficulties  may  be 
overcome  by  slight  changes,  either  in  the  digging  part  of  the  dredge 


8 


GOLD  DREDGING  IN  CALIFORNIA. 


or  in  the  gold-saving  appliances;  but  some  of  them,  such  as  hard  bed- 
rock, in  cases  are  fatal  to  successful  dredging. 

The  conditions  bearing  on  the  cost  of  operation  are  such  that  each 
tract  of  ground  becomes  a  problem  in  itself,  and  any  attempt  to  use  the 
costs  obtained  under  one  set  of  conditions,  on  which  to  predicate 
those  which  would  hold  under  another,  without  a  thorough  knowledge 
of  the  various  elements  which  enter  into  the  problem,  will  lead  to  large 
discrepancies  between  the  results  predicted  and  those  actually  obtained, 
with  a  possible  consequent  failure  of  the  enterprise.  . 

There  have  been  built  in  California  many  dredges  that  have  failed 


AN  -OLD    TIMER,' 


ILLUSTRATIN(;    ONE    OF    TH 
DREDGE  BUILDINC;. 


EARLY    MISTAKES  OF 


and  become  total  losses.  Yet  to-day,  with  all  the  data  at  hand  for  any 
careful  investigator,  there  should  be  little  excuse  for  failure.  The 
varying  conditions  that  exist  where  dredging  is  being  done  at  Oroville, 
Folsom,  in  Trinity  County,  in  Idaho,  Montana,  Colorado,  British 
Columbia,  the  Klondike,  Alaska,  and  New  Zealand,  both  as  to  the 
digging  of  the  gravel  and  the  saving  of  the  gold,  give  the  miner  the 
actual  experience  necessary  for  him  to  come  to  conclusions  under  most 
circumstances. 

The  illustration  entitled  "An  Old  Timer"  illustrates  one  of  the  early 
mistakes  in  dredge  building  in  this  State.     This  machine,  on  which 


10  GOLD  DREDGING  IN  CALIFORNIA. 

some  $40,000  was  expended,  is  very  odd,  in  view  of  later  improved 
gold  dredges.  The  bucket  ladder  is  made  of  two  pieces  of  4-inch  by 
18-iuch  Oregon  pine.  The  buckets  are  made  of  No.  14  iron;  the  links 
of  %-inch  by  2-inch  tire-iron,  and  put  together  with  i/o-inch  carriage 
bolts.  It  was  driven  first  by  steam  and  then  by  a  gasoline  engine.  It 
is  reported  to  have  dug  8,000  yards  in  the  period  between  March,  1902, 
and  July,  1904.  Its  running  time  could  hardly  have  been  over  one 
hour  per  day,  being  shut  down  almost  constantly  for  repairs.  It  now 
stands  idle  in  ground  that  dredged  30  cents  per  cubic  yard. 

The  single-bucket  or  spoon  dredge  was  evolved  in  New  Zealand  in 
the  early  sixties,  and  was  worked  entirely  by  hand.  A  steam  single- 
bucket  dredge  was  built  in  1870.  About  1880,  bucket  and  ladder 
dredges  were  introduced.  These  were  nearly  all  worked  with  power 
furnished  by  current  wheels.  The  first  steam  chain  bucket  dredges  of 
the  present  type  were  introduced  about  1882.  One  dredge  of  this 
class,  built  about  that  time,  was  successfully  worked  for  sixteen  years. 
On  account  of  the  success  of  a  dredge  in  1889,  on  a  branch  of  the 
Molyneux  River,  some  twenty  were  built  at  an  average  cost  of  $17,500, 
but  were  failures,  owing  mainly  to  the  fact  that  the  ground  was  not 
suitable  for  dredging  and  the  management  bad.  Many  of  these  dredges 
were  floated  down  to  the  Molyneux  River,  and  under  new  ownership 
were  made  successful.  Then  a  number  of  suction  dredges  were  built, 
but  proved  complete  failures.  Since  then,  the  endless-chain  bucket 
dredge,  similar  to  those  used  in  California,  has  held  the  field.  In  New 
Zealand,  at  the  end  of  1902,  there  were  201  dredges  working,  52  stand- 
ing, 23  building,  14  under  removal,  and  2  wrecked— a  total  of  292. 

The  first  successful  endless-chain  bucket  dredge  in  the  United  States 
w^as  built  in  1894  at  Grasshopper  Creek,  in  Montana.  Many  attempts 
to  dredge  had  been  made  on  the  Pacific  Coast,  but  it  was  not  until  1897 
that  a  dredge  of  the  present  ty^DC  was  built  in  California.  In  the  sum- 
mer of  1895,  W.  P.  Hammon  and  Warren  Treat,  who  were  interested 
in  horticulture  near  Oroville,  wel'e  working  some  gravels  for  gold  on 
property  now  owned  by  tlie  Feather  River  Exploration  Company.  Mr. 
Treat  had  made  a  pit  about  100  feet  square  down  to  bedrock,  using  a 
centrifugal  pump  to  keep  the  water  out,  and  hauling  the  gravel  in 
wagons  out  to  small  sluice-boxes,  where  it  was  w^ashed.  The  gravel  was 
handled  several  times  by  manual  labor,  and  in  spite  of  the  heavy  costs 
for  labor  and  pumping  water,  there  was  a  profit.  Mr.  Hammon  had 
another  pit,  but  on  approacliing  bedrock  found  that  the  great  amount 
of  water  coming  in  would  make  mining  at  a  profit  difficult. 

My  attention  was  called  to  these  cases  and  I  visited  the  property, 
and,  after  consulting  with  Mr.  Hammon  as  to  the  best  process  for 
working,  suggested  hydraulic  elevators;  but  it  Avas  found,  on  investi- 


12 


GOI-D    DREDGING    IN    CALIFORNIA. 


gation,  that  the  distance  necessary  to  convey  water  and  the  large 
amount  of  water  in  the  ground  itself,  to  be  handled,  would  make  this 
impracticable.  At  that  time  little  was  known  of  dredging  in  Califor- 
nia. However,  I  had  purchased  some  of  the  land  through  Mr.  Hara- 
mon  and  A.  F.  Jones.  A  few  months  later  I  met,  in  San  Francisco, 
Capt.  Thomas  Couch  and  F,  T.  Southerland,  from  Montana,  who  were 
looking  for  mining  properties.  To  them  I  suggested  the  Feather  River 
gravels,  and  there  they  went,  and,  with  Mr.  Hammon,  after  prospect- 
ing for  about  a  year,  purchased  1,000  acres,  which  is  now  being  worked 
by  five  dredges. 


^W^tmdl^^ 

m^ 

h. 

/       ^      ., 

ILL.    No.    (■).     DREDGE   No.    1,   FEATHER    RIVER    EXPLORATION    COMPANY,    OROVILLE. 
RISDON  TYPE.     FIRST  SUCCESSFUL  DREDGE  IN  CALIFORNIA;  STILL  OPERATING. 


While  they  were  prospecting  this  ground,  R.  H.  Postlethwaite,  a 
New  Zealand  engineer,  who  had  come  to  California  to  look  over  the 
dredging  field,  had  constructed,  by  the  Risdon  Iron  Works,  a  314  cu.  ft. 
bucket  dredge,  to  be  used  near  Smartsville,  on  the  Yuba  River.  While 
the  dredge  itself  was  satisfactory,  the  conditions  did  not  permit  of  a 
financial  success  in  working. 

The  first  dredge  at  Oroville,  built  for  the  Feather  River  Exploration 
Company,  began  work  March  1,  1898.  It  was  designed  by  Mr, 
Postlethwaite,  and  built  by  the  Risdon  Iron  Works.  This  dredge  is 
still  being  successfully  operated;  it  has  been  strengthened,  however,  in 
parts. 


14  GOLD  DREDGING  IN  CALIFORNIA. 

Steam  was  used  at  first,  but  now  all  the  dredges  in  the  Sacramento 
Valley  districts  are  worked  by  electric  power.  During  the  first  two 
years  of  successful  dredging  at  Oroville  with  endless-chain  bucket 
dredges,  a  number  of  attempts  were  made  to  dredge  with  suction  and 
other  styles  of  dredges,  but  all  these,  with  the  exception  of  one  s.team 
shovel  dredge,  were  failures. 

AREA   OF   DREDGE  GRAVEL. 

The  following  table  will  show,  in  a  general  way,  the  acreage  of 
gravel  under  consideration  for  dredging.  It  is  probable  that  these 
figures  will  in  many  cases  be  increased  and  other  districts  opened: 

Average  VaUie 
per  Cubic  Yard, 
District.  Acreage.  in  cents. 

Oroville 7,5(X)                            17 

Yuba  River t 5,000                 25  to  30 

Bear  River 1,000                 18  to  30 

Folsom 5,000                 15  to  25 

Calaveras 350                  16  to  22 

Stanislaus 1,200                 15  to  30 

Trinity 1,000 

Shasta 1,500 

Siskiyou 1,000 

Plumas 1,500 

Total 25,050 

In  Stanislaus  County  considerable  prospecting  has  been  done,  and 
about  1,200  acres  has  been  proved  to  contain  values  sufficient  to  war- 
rant dredging. 

In  Shasta  County,  drilling  is  being  done  on  Cottonwood  Creek  and 
on  land  opposite  Redding  on  the  Sacramento  River,  and  on  Clear  Creek. 

In  El  Dorado  County  some  land  on  the  South  Fork  of  the  American 
River,  near  Coloma,  is  being  considered,  but  not  yet  reported  proved. 

In  all  these  districts,  and  at  other  points  in  the  Sacramento  water- 
shed especially,  there  are  considerable  areas  of  dredge  gravel,  most  of 
which  have  been  more  or  less  examined,  but  not  proved  to  be  of  suffi- 
cient value  to  work  at  the  present  cost. 

The  best  dredge  authorities  claim  that  by  proving  good  grade  of  pay 
in  some  of  this  outlying  ground  and  reducing  working  costs,  at  least 
25,000  acres  will  in  time  be  added  to  the  fields  which  it  is  already 
decided  to  dredge  in  the  Sacramento  Valley. 

In  this  connection  experiments  are  being  made  with  a  view  to  work- 
ing by  a  process  similar  to  the  present  dredging  system,  but  at  much 
lower  cos,t.  Those  interested  do  not  care  to  give  out  any  data  at 
present. 


GOLD  DREDGING  IX  CALIFORNIA.  15 

It  may  seem  a  simple  thing,  to  those  who  know,  to  say  that  there  is  a 
great  diversity  in  methods  of  gravel  mining  caused  by  varying  con- 
ditions of  the  deposits,  and  that  the  method  in  vogue  in  one  case  may 
mean  failure  in  another.  Yet  the  want  of  this  knowledge  has  been  the 
cause  of  immense  waste  of  capital.  There  have  been  large  simi^  of 
money  lost  in  trying  to  hydraulic  drifting  ground.  Attempts  have 
been  made  to  use  hydraulic  elevators  to  work- dredging  ground,  where 
there  was  an  excess  of  water  to  be  handled.  Dredges  have  been  built 
to  work  ground  that  could  be  worked  only  by  means  of  hydraulic 
elevators.  There  are  many  thousands  of  acres  of  gravel,  mostly 
lacustrine  deposits,  in  California  and  other  states  and  territories  on 
the  Pacific  Coast  and  in  Alaska  that  is  free  from  water  and  should  be 
worked  with  steam  shovels,  which  people  are  now  exploiting  with  a 
view  to  working  with  dredges.  In  other  words,  they  are  proposing  to 
make  a  condition— by  flooding  the  ground  with  water— that  means  an 
unnecessary  cost.  A  study  of  the  conditions  existing  wiU  lead  to  con- 
elusions  as  to  methods  to  be  adopted;  and  in  this  way  only  can 
economic  success  be  made. 

The  different  kinds  of  gravel  raining,  it  may  be  said,  are : 

First — Ordinary  hydraulic  mining,  requiring  water  under  pressure 
and  a  good  dump,  with  gravel  easily  removable. 

Second — There  are  the  drift  mines  in  layers  of  gravel  deposits  over- 
capped  with  lava  or  other  material  of  such  great  depth  that  only 
underground  or  drift  mining  is  possible. 

T/i /re?— There  are  the  bars  along  the  rivers,  based  on  hard  bedrock, 
that  must  be  worked  with  hydraulic  elevators  for  want  of  dumping 
facilities,  and  which  can  not  be  worked  with  dredges  because  the  bed- 
rock is  hard.  Yet,  in  these  cases  it  must  be  understood  that  even 
hydraulic  elevators  are  of  no  use  if  there  is  an  excess  of  water. 

Fourth — There  is  the  gravel  with  an  excess  of  water,  with  soft  bed- 
rock, that  can  only  be  worked  with  dredges. 

It  would  be  futile  to  hydraulic  the  lava-capped  di^ddes  in  Placer 
and  other  counties  in  California ;  yet  this  has  been  attempted.  They 
must  be  drifted. 

It  would  be  impossible  to  make  an  economic  success  of  the  use  of 
hydraulic  elevators  at  Oroville  or  Folsom,  on  account  of  the  excess  of 
water  in  the  gravel ;  yet  this  has  been  attempted. 

In  some  mountainous  districts  in  California,  dredges  have  been  tried 
and  have  proved  failures,  because  the  bedrock  was  too  hard  to  dig  and 
the  gold  could  not  be  lifted. 

Then  there  are  cases  where  the  excess  of  water  prevents  the  use  of 
hydraulic  elevators,  and  the  hardness  of  the  bedrock  and  the  conse- 
quent conditions  that  usually  follow  prevent  the  use  of  dredges.     Yet 


16  GOLD  DREDGING  IN  CALIFORNIA. 

inventions  not  now  known  may  be  made  to  work  these  gravels  at  a 
profit. 

Then  again,  there  are  large  tracts  of  gravel,  usually  of  lacustrine 
deposit,  in  the  Sierras,  not  deep,  and  not  overcapped  with  lava,  that 
afford  good  opportunity  for  the  use  of  steam  shovels. 

GEOLOGY. 

While  dredge  mining  is  being  conducted,  under  conditions  appar- 
eiitlv  satisfactory  to  those  engaged  in  the  industry,  in  the  Sacramento 
Valley  districts  of  Oroville,  Yuba,  Folsom,  and  Calaveras,  and  on  the 
Bear  River,  there  is  an  interesting  geological  feature  worthy  of  more 
than  a  passing  thought,  and  that  is  that  all  of  this  dredging  is  being 
done  on  what  may  be  considered  a  superficial  layer  of  gravel,  under- 
laid by  a  stratum  of  volcanic  mud  and  pand,  the  deposition  of  which, 
of  course,  antedated  the  deposition  of  this  gravel. 

The  gold-bearing  veins  existed  and  were  eroded  for  a  great  period  of 
time,  antedating  the  volcanic  activity  which  is  such  a  prominent 
feature  of  the  Sierra  Nevadas,  and  the  ancient  rivers  deposited  their 
gold-bearing  debris  upon  the  original  bedrock,  both  within  the  limits 
of  their  rims  and  upon  the  floor  of  the  great  interior  valley — the 
present  valley  of  the  Sacramento  River— which  at  that  time  was  a  vast 
fresh-water  lake. 

Subsequently  the  volcanic  activity  resulted,  in  many  instances,  in 
filling  the  old  gold-bearing  rivers  to  the  brim  with  a  vast  quantity  of 
volcanic  material,  now  recognized  in  the  mud,  tufa,  and  breccia  over- 
lying the  ancient  river  channels,  and,  as  a  matter  of  course,  this 
volcanic  material  was  carried  out  into  the  estuaries,  extending  even 
into  the  lake  itself  to  a  considerable  distance,  and  covering  the  pre- 
viously deposited  gold-bearing  gravel.  The  subsequent  uplift  of  the 
whole  Sierra  Nevada  system  has  resulted  in  the  exposure  of  these  lake- 
beds  along  the  eastern  edge  of  the  Sacramento  Valley. 

The  subsequent  erosion  of  modern  streams,  cutting  through  the 
original  ancient  river  channels,  and  often  into  the  underlying  bedrock, 
with  its  complex  system  of  gold-bearing  veins,  resulted  in  the  formation 
of  a  later  bed  of  gravel,  which  rests  upon  the  volcanic  sands  and  mud 
of  the  lake. 

Doubtless  this  process  has  been  repeated  a  number  of  times,  and  this 
point  could  be  determined  by  drilling  or  by  sinking  shafts.  But  it  is 
clearly  evident  that  the  present  dredging  is  not  in  deposits  of  gravel 
resting  on  the  true  bedrock— the  slates  and  schists  which  form  the 
adjacent  foothills— but  in  later,  and,  quite  likely,  less  valuable  gravel. 

In  many  ancient  river  channels  there  are  sometimes  two  or  three 
gold-bearing  strata,  called  by  the  miners  "leads,"  and  the  stratum 


GOLD  DREDGING  IN  CALIFORNIA.  17 

of  gravel  on  the  bedrock  is  usually  the  richest,  while  the  upper  strata 
are  relatively  of  less  value  in  gold  per  cubic  yard.  There  are,  how- 
ever, instances  contrary  to  this,  where  one  of  the  upper  strata  is  of  more 
value;  but  this  Is  due  to  local  conditions,  probably  generally  to  the 
erosion  of  other  preexisting  beds  of  gravel.  Why  this  principle  should 
not  be  proved  true  in  this  lake  is  well  worth  considering. 

Similar  conditions  have  been  found  to  exist  in  the  Cariboo  country 
in  British  Columbia,  and  in  some  of  the  mountain  districts  of  Cali- 
fornia outside  of  the  Sacramento  Valley  region. 

The  discovery,  however,  of  good  value  in  these  lower  strata  might 
not  lead  to  satisfactory  economic  results,  because  the  expense  of  hand- 
ling large  bodies  of  water  that  might  be  encountered  would  handicap 
any  venture  in  that  direction. 

AGRICULTURE. 

The  question  of  reclaiming  these  lands  for  agriculture  after  they 
shall  haA'e  been  dredged  is  hardly  worth  discussing  at  present ;  but,  in 
course  of  time,  as  farming  lands  become  more  valuable,  they  could  be 
leveled  with  scrapers  run  by  electric  power  and  then  covered  with 
soil  hydraulicked  in  the  foothills  and  run  down  by  flume.  In  the 
meantime,  however,  a  large  proportion  of  the  rocks  will  disintegrate 
and  so  make  soil. 

However,  should  these  lands  be  reclaimed,  their  average  value  for 
agriculture  would  be  much  higher  than  it  was  before  they  were  sold  to 
the  dredge  companies.  Some  of  them  were  unfit  for  cultivation  and 
very  little  were  worth  more  than  from  $15  to  $35  per  acre  in  the  Oroville 
district,  but  probably  as  much  as  from  $50  to  $60  per  acre  in  the  Folsom 
district.  A  small  proportion  was  covered  with  orchards  and  vine- 
yards, and  so  was  worth  more.  Yet,  as  much  as  $1,000  per  acre  was 
paid  by  the  miners  for  some  land  about  Oroville,  and  an  average  of 
about  $100  per  acre  for  the  whole  Oroville  tract.  In  other  words,  the 
owners  received  from  the  miners  from  three  to  five  times  the  value  of 
their  property  for  agriculture  in  this  district. 

Granting  that  these  lands  will  never  be  reclaimed,  it  may  be  asked,  is 
not  their  destruction  a  distinct  benefit  to  the  State?  Take  the  Oro- 
ville district,  for  instance.  The  farm  owners  have  received  nearly  a 
million  dollars  for  their  land.  There  have  been  built  over  thirty 
dredges  and  several  shops,  at  a  cost  of  nearly  $2,000,000,  a  large  part 
of  which  has  been  paid  in  wages.  Probably  as  many  more  dredges  will 
be  built  before  the  tract  is  worked  out.  It  is  estimated  that  the  cost  of 
repairs  and  renewal  of  parts  during  the  life  of  each  dredge  will  amount 
to  as  much  as  the  first  cost.  It  would  take  twenty  years  with  thirty 
dredges  to  work  the  tract,  and  this  means  the  employment  of  at  least 
500  men,  with  families  dependent  upon  them,  to  say  nothing  of  the 


18 


GOLD  DREDGING  IN  CALIFORNIA. 


men  employed  in  the  buiiding  of  the  dredges  and  in  the  shops.  This 
means  the  payment,  in  wages,  of  over  $1,000,000  a  year,  and  a  livelihood 
for  two  or  three  thousand  people,  if  we  include  those  dependent  upon 
the  wage-earners.  From  this  tract  will  be  produced  in  gold,  to  be 
added  to  the  wealth  of  the  State,  about  $60,000,000. 

From  the  dredging  ground  in  the  Sacramento  Valley  districts 
(estimated  at  25,000  acres)  which  have  been  proved,  and  which  it  has 
been  decided  to  work,  there  should  be  produced  an  average  of  15  cents 
per  cubic  yard;  and  if  we  allow  a  depth  of  9  yards,  the  estimated 


8.     TAILINGS    PILES    AFTER     DREDGING. 
OROVILLE. 


MARIGOLD   DREDGING   COMPANY, 


25,000  acres  will  produce  $163,350,000  in  gold,  to  be  added  to  the 
wealth  of  the  State. 

Placing  the  average  value  of  all  this  ground,  both  that  which  is  and 
that  which  is  not  suitable  for  agriculture,  at  $40  per  acre  for  that  pur- 
pose, the  loss  amounts  to  no  more  than  $1,000,000. 

In  connection  with  the  question  of  reclaiming  these  dredging 
grounds,  it  may  be  mentioned  that  James  H.  Leggett,  owner  of  dredges 
at  Oroville,  has  begun  some  experiments  by  planting  eucalyptus  and 
olive  trees  on  the  rock  piles,  with  a  few  spadefuls  of  earth  at  the  roots 
of  each  tree,  and  they  are  thriving.  In  New  Zealand,  experiments 
with  a  view  to  making  forest  land  of  the  dredge  ground  are  reported 
to  be  meeting  with  success. 


GOLD  DREDGING  IN  CALIFORNIA.  19 


YIELD  FOR  1903. 


The  output  in  gold,  in  1903,  from  all  the  dredges  in  California, 
according  to  the  returns  made  to  the  United  States  Mint,  was 
$1,475,749.  The  yield  for  1902  was  $867,665,  showing  an  increase  of 
$608,084  for  1903.  The  returns  for  1903  were  from  25  dredges  in  the 
Oroville  district  in  Butte  County,  3  dredges  in  the  Folsom  district  in 
Sacramento  County^  1  dredge  in  Siskiyou  County,  1  dredge  in  Trinity 
County,  and  1  dredge  in  Yuba  County.  Of  the  total  for  1903, 
$1,329,998  came  from  Butte  County,  meaning  the  Oroville  district. 
There  will  be  an  increase  for  1904  beyond  the  proportionate  increase 
in  the  number  of  dredges,  because  the  new  dredges  are  of  larger 
capacity  and  improvements  have  been  made  in  the  old  dredges. 

At  the  beginning  of  1905  there  were,  in  the  Oroville  district,  28 
dredges;  in  Calaveras  County,  1  dredge;  in  the  Folsom  district,  5 
dredges ;  in  Shasta  County,  2  dredges ;  in  Trinity  County,  1  dredge ;  in 
Siskiyou  County,  1  dredge;  in  Yuba  County,  2  dredges;  total,  40 
dredges,  as  against  31  dredges  for  1903.  Some  of  the  dredges  worked 
only  part  of  1903,  having  been  built  during  the  year.  Taking  into 
consideration  the  increased  average  yardage  of  these  dredges  and  the 
fact  that  a  number  of  new  ones  will  be  in  operation  during  part  of  the 
year,  the  yield  for  1905  may  be  expected  to  be  considerably  more  than 
double  that  of  1903. 

THE  DREDGE. 

The  continuous-chain  bucket  dredge  is  practically  the  only  type  that 
is  in  successful  operation  in  the  gravels  of  the  Sacramento  Valley  dis- 
tricts. New  Zealand,  Montana,  Idaho,  Colorado,  and  Oregon,  and  it 
holds  the  field  in  gravel  where  there  is  an  excess  of  water  and  where 
conditions  are  generally  favorable  for  dredging.  There  are  many  dif- 
ferences in  detail  in  the  different  dredges,  but  under  favorable  con- 
ditions, such  as  exist  in  the  Sacramento  Valley  district,  in  New  Zealand, 
in  the  States  named,  and  in  Alaska,  the  results  obtained  from  these 
dredge-s  do  not  differ  much  except  where  the  conditions  are  abnormal 
and  difficult.  The  dredge  in  use  is  much  like  the  ordinary  continuous- 
chain  bucket  dredge  used  for  other  work,  so  far  as  the  digging  part 
goes,  except  that  the  size  of  shaftings  and  strength  and  weight  of  all 
parts  are  greatly  increased.  For  gold  mining  it  consists  of  a  hull,  a 
digger,  screen,  sluice-table  and  sluice-boxes,  a  stacker,  a  pump,  amalga- 
mator, and  sometimes  a  sand  pumpj  with  lines  or  lines  and  spuds  to 
hold  the  boat  in  position,  and  separate  motors  for  each  part  where 
power  is  required. 


20 


GOLD  DREDGING  IN  CALIFORNIA. 


Hull.  — So  far,  in  California,  all  the  hulls  are  made  of  wood,  but 
some  dredges  sent  to  Dutch  Guiana  have  been  built  with  steel  hulls. 
This  hull  is  rectangular  in  shape,  with  a  slightly  reduced  width  in  the 
bow  of  the  boat.  As,  practically  speaking,  all  the  parts  of  the 
machinery  of  a  dredge  are  renewed  during  the  life  of  the  dredge,  it 
has  been  suggested  that  steel  hulls  would  give  a  longer  life  and  more 
solidity ;  but  so  far  none  have  been  constructed,  and  probably  will  not 
be  until  there  is  a  nearer  approach  to  perfection  of  the  machinery  and 
a  better  knowledge  is  had  of  the  limits  of  the  capacity  of  the  dredges, 


ILL.  N.i.  :>.     HULL  OF  BOSTON  AND  ORoVILLL    DREDfilNd    COMPANY'S    DRED(iE,  ORO- 
VILLE,  IN  COURSE  OF  CONSTRUCTION  IN   1901. 

for  the  tendency  is  to  discard  the  smaller  dredges  and  to  build  those  of 
larger  capacity. 

To  allow  the  digging  ladder  and  its  chain  of  buckets  to  descend  to 
the  bottom  of  the  ground  to  be  worked,  the  hull  in  the  forward  part  is 
divided  by  an  opening  called  the  well,  in  Avhich  the  ladder  is  moved  up 
and  down.  The  dimensions  of  the  hull  vary  with  the  size  of  the 
buckets,  as  may  be  seen  by  reference  to  the  accompanying  folder  of 
particulars  as  to  dredges.  The  hulls  vary  in  width  from  30  to  40  feet, 
in  length  from  80  to  120  feet,  and  in  depth  from  7  to  9  feet. 


Gauntries.— y.ear  the  center  of  the  hull  there  is  a  main  gaimtry,  to 
support  the  upper  end  of  the  digging  ladder  and  the  main  drive  of  the 


22 


GOLD  DREDGING  IN  CALIFORNIA. 


bucket  chain.  These  have  commonly  been  made  of  wood,  but  lately 
some  have  been  constructed  of  steel  plates.  There  is  a  stern  gauntry 
to  support  the  tail  sluices,  the  conveyor  ladder,  and  the  spuds,  if  they 
are  used. 

Digger. — This  consists  of  a  ladder  frame,  built  strongly  of  iron  or 
steel,  so  that  a  chain  of  buckets  may  travel  continuously  around  its 
length.  On  the  best  of  these,  manganese  steel  is  used  in  the  lips  and 
bushings  of  the  bucket,  and  on  the  ladder  rollers.  It  has  been  found 
that  a  large  saving  in  cost  of  repairs,  which  is  the  main  cost,  and 


ILL.  No.  n.     DETAILS  OF  BUCKET  CHAIN,  LATEST  TYPE  BUCYRUS  DREDGE— BIGGS  No.  2. 

where  future  saving  can  be  made  in  the  cost  of  dredging,  is  in 
strengthening  the  wearing  parts  of  these  buckets  and  links.  A  refer- 
ence to  the  tables  of  cost  will  show  how  large  is  the  proportion  of  the 
cost  of  working  caused  by  the  breaking  of  buckets  and  other  parts  of 
the  digger.  However,  this  has  been  very  much  reduced  since  the  first 
successful  work  was  done  at  Oroville,  and  is  being  continually  reduced 
as  new  dredges  are  constructed.  The  greatest  improvements  are  now 
being  made  by  the  use  of  special  steels  and  in  the  shape  of  the  buckets. 
The  bucket  line  is  either  what  is  called  of  a  "close  connection"  or  of 
an  "open  connection";  that  is,  the  buckets  follow  each  other  on  each 
link  of  the  chain,  or  there  are  open  linlcs  between  the  buckets.     Wher- 


GOLD  DREDGING  IN  CALIFORNIA. 


23 


ever  there  are  no  large  bowlders  and  the  gravel  is  comparatively  loose, 
there  can  be  no  question  that  the  close-connected  buckets,  with  less 
speed,  will  dig  more  ground  than  will  the  open-connected.  As  to  the 
difference  between  the  open-  and  the  close-connected  bucket  in  hard 
ground,  the  question  as  to  the  greatest  capacity  has  not  been  settled, 
but  it  is  probable  that  the  close-connected  bucket  will  give  more  sat- 
isfactory results.  However,  where  there  are  large  bowlders,  the  open 
connection  must  be  used,  or  the  backs  of  the  buckets  will  be  jammed 
and  broken.  The  close-connected  buckets  are  run  at  a  lower  rate  of 
chain  speed  than  the  open-connected  buckets,  the  former  moving  at  the 


ILL.  No.  12.     DIGGING  END  OF  "  EL  DORADO  No.  1,"  IMPROVED  RISDON  TYPE,  INTER- 
MITTENT BUCKET. 


rate  of  about  50  feet,  or  18  to  25  buckets,  per  minute,  and  the  latter  at 
the  rate  of  60  feet,  or  12  to  15  buckets,  per  minute.  Yet,  in  hard 
ground  the  open-connected  buckets  are  filled  to  their  full  capacity  more 
often  than  are  the  close-connected  buckets.  In  this  connection  it  may 
be  said  that  most  of  the  newer  dredges  at  Oroville  and  Folsom  are 
equipped  with  close-connected  buckets. 

Owing  to  the  greater  weight  of  the  close-connected  chain  of  buckets 
and  greater  yardage  handled,  more  power  is  required  than  for  open- 
connected  buckets.  The  following  tables  will  give  an  idea  of  this 
difference : 


ILL.  No.  13.     BUCYRUS   MACHINE   STARTING    CUT    IN  TOP   (xROUNI).     VILORO    DREDGE, 
OROVILLE   FIELD. 


ILL.  No.  14.     BUCKET  LINE  IN  OPERATION.     LAVA  BEDS  DREDGE  No. 


GOLD  DREDGING  IN  CALIFORNIA.  25 

The  different  motors  in  the  Oroville  Gold  Dredging  and  Exploration 
Company's  5-foot  Risdon  dredge  are  of  the  following  capacities: 

Horse-power. 

Main  drive _- 50 

Stacker  and  screens 20 

Sidelines  and  head  lines . 10 

Ladder  hoist 15 

Water  pump 40 

Primer  pump 3 

Total 138 

The  average  amount  of  horse-power  used  in  the  dredge  was  90.  No 
returns  were  made  of  the  proportion  of  the  full  capacity  of  each  motor 
used. 

The  following  figures  are  given  by  the  builders  of  the  Bucyrus, 
close-connected,  belt-convej'or,  shaking  screen  dredges,  as  to  the  horse- 
power of  the  motors  as  built : 


Dredge  with  3  cu.  ft.  Buckets.  Horse-power. 

Digging  motor 50 

Winch  motor 15 

Screen  and  conveyors 20 

Water  pump 30 

Sand  pump -- 30 

Priming  pump 3 

Total 148 

Actual  consumption,  about  100  H.  P. 

Dredge  with  5  cu.  ft.  Buckets. 

Digging  motor 75  or  100 

Winch  motor 20 

Screen 15 

Conveyor 10  or  15 

Water  pump 50 

Sand  pump 30 

Priming  and  clean-up 5 

Total 235 

Actual  consumiition,  about  125  to  150  H.  P. 

Dredge  with  6  cu.  ft.  Buckets. 

Digging  motor 100 

Winch  motor 30 

Screen 15 

Stacker 15 

Water  _-- 50 

Sand  pump 50 

Priming  and  clean-up 7^ 

Total 2671 

Actual  consumption,  not  known  yet. 


26  GOLD  DREDGING  IN  CALIFORNIA. 

The  following  data  have  been  given  as  to  the  actual  consumption  of 
power,  as  per  report  in  L.  J.  Hohl's  paper  read  before  the  California 
Miners'  Association: 

For  a  3  cu.  ft.  close-connected  bucket  dredge,  with  shaking  screen 

and  belt  conveyor:  Horse-power. 

Main  drive 26  to  45 

Stacker  and  screen 12  to  16 

Water  pump 45  to  50 

Winches,  maximum 28 

Sand  pump 32  to  50 

For  a  5  cu.  ft.  dredge  of  the  same  type: 

Main  drive 42  to  70 

Stacker  and  screen 10  to  20 

Water  pump 50  to  75 

Winches,  maximum 27 

Sand  pump,  not  tested. 

For  a  5  cu.  ft.  open-connected  bucket  dredge,  with  revolving  screen  and 
bucket  conveyor : 

Main  drive 60 

Water  pump 52 

Screen  and  stacker 18| 

Other  motors,  not  tested. 

Yuba  dredge,  6  cu.  ft.  buckets,  close-connected,  with  shaking  screen  and 
belt  conveyor.     This  dredge  digs  60  feet  deep : 

Main  drive 108 

Watei  pump 68 

Sand  pump 63 

Stacker 9 

Shaking  screen 11 

Auxiliary  supply 13 

Buckets.  — The  buckets  at  Folsom,  Oroville,  and  Yuba  vary  in  size 
from  3  cubic  feet  capacity  up  to  8^  cubic  feet,  and  it  is  proposed  now 
to  build  a  dredge  at  Folsom  with  buckets  of  13  cubic  feet  capacity. 
They  vary  considerably  in  shape,  and  in  the  material  used,  but  some 
of  the  best  are  those  that  are  made  with  a  cast  nickel  steel  bottom 
piece,  with  sheet  steel  hood  and  manganese  steel  lips,  and  reinforced 
cutting  edges.  If  a  comparison  could  be  made  as  to  the  breakage  and 
consequent  extra  cost  between  the  earlier  buckets  made  and  those  now 
being  turned  out,  a  great  advance  would  be  shown,  and  greater 
advances  are  possible.  This  is  a  matter  for  the  consideration  of  the 
manufacturers  and  the  engineers  in  charge  of  the  plants. 

As  to  the  difference  in  cost  of  operating  under  favorable  and  simi- 
lar conditions  with  the  different  sized  buckets,  it  may  be  said  that 
the  cost  for  labor  is  nearly  the  same  for  the  small  as  for  the  large 
dredge,  and  much  smaller  per  cubic  yard  for  the  larger;  that  there 
is  a  proportionately  smaller  cost  for  power  and  for  repairs.  Manage- 
ment and  all  other  expenses  are  reduced  in  the  larger  dredges,  pro- 


ILL.  No.  17.     OPEN-CONNECTED  BUCKETS,  RISDON  TYPE,  5  CU.  FT.  CAPACITY. 


30  GOLD  DREDGING  IN  CALIFORNIA. 

vided,  of  course,  that  in  their  construction  there  is  given,  by  the 
strengthening  of  the  parts,  as  little  loss  by  breakdowns.  Then,  it  may 
be  said,  that  the  larger  buckets  will  handle  larger  bowlders  and  so 
decrease  the  breakage  in  the  bucket  line.  The  parts  being  heavier,  it 
is  possible  to  dig  harder  ground.  The  increased  yardage  handled  will 
mean  a  decrease  in  the  interest  cost  on  the  original  investment.  As 
against  this,  it  may  be  said  that  the  first  cost  is  much  larger,  and  that 
better  equipped  repair  shops  are  required. 

The  weakest  portions  of  the  bucket  bottom  are  the  eyes  and  the 
parts  coming  in  contact  with  the  manganese  or  nickel  steel  wearing 
plates  of  the  upper  and  lower  tumblers.  As  these  wear  there  is  an 
increase  in  danger  of  breakage,  and  it  is  to  the  manufacturers  that 
we  must  look  for  remedies  in  this  respect,  by  the  addition  of  more 
metal  to  add  strength  and  compensate  for  wear,  by  improvement  in 
the  character  of  the  steel  used,  and  by  changes  in  the  faces  of  the 
tumblers  in  order  to  give  better  bearing  and  reduce  the  strain.  Simpler 
and  stronger  parts  of  the  best  materials  must  be  used  to  remedy  the 
present  evils. 

Spuds  and  Head  Lines.— To  keep  the  dredge  in  place,  move  it  about, 
and  hold  it  against  the  bank,  there  are  two  methods  in  use:  (1)  Two 
spuds,  one  of  steel,  and  one  of  wood  at  the  stern  of  the  boat— the 
wooden  spud  being  used  when  the  steel  spud  is  lifted  and  it  is  desired 
to  "walk"  the  boat  ahead.  At  the  forward  end  of  the  boat  are  two 
steel-wire  rope  lines  fastened  to  the  shore  to  move  the  boat  to  right 
and  left  through  an  arc  of  a  circle,  and  two  at  the  stern.  (2)  Instead 
of  spuds  and  lines,  five  lines  are  used — two  at  the  stern,  two  forward, 
and  one  ahead  to  hold  the  boat  against  the  bank. 

In  the  lighter  and  softer  ground  in  New  Zealand,  the  guy  method 
seems  to  be  preferred,  but  in  Oroville  both  methods  are  in  vogue. 

Where  the  surface  of  the  ground  is  level,  and  the  ground  to  be 
dug  is  soft  and  shallow,  some  of  the  dredge  owners  prefer  the  lines. 
An  uneven  surface  of  the  ground,  hard  gravel  or  deep  gravel  makes 
the  spuds  preferable.  Most  of  the  largest  operators  in  Oroville  equip 
boats  with  both,  but  use  the  head  line  only  in  emergencies.  When 
using  guys  only,  the  digging  must  be  done  only  from  the  bottom;  while 
with  the  spuds  the  bank  may  be  cut  in  terraces,  and  this  is  sometimes 
preferable  in  deep  ground. 

In  deep  ground  when  cutting  the  bank  by  digging  from  the  bottom 
up  in  terraces,  or  down,  there  is  less  danger  of  injury  to  the  bucket 
line  and  cleaner  lifting  of  all  gravel  if  spuds  are  used.  This  means 
that  there  would  be  less  loss  of  pay  gravel  caved  down  behind 
where  the  digger  is  working,  and  less  loss  of  time  and  consequent 


32 


GOLD  DREDGING  IN  CALIFORNIA. 


less  loss  of  capacity  in  yardage.  However,  several  operators  state 
that  with  a  head  line  instead  of  spuds  in  digging  deep  ground,  the 
dredge  may  be  moved  more  quickly  in  case  of  heavy  caving  of  the 
bank,  and  so  save  accidents.  Then,  again,  the  use  of  the  head  line  gives 
an  easier  and  more  even  distribution  of  the  tailings,  and,  it  is  claimed, 
makes  the  sand  pump  unnecessary. 


ILL.  No.  19.     TAILINGS  STACKER,  BELT  CONVEYOR. 

The  Stacker.— There  are  two  types  of  stackers  in  use  in  California- 
one  the  ordinary  belt  conveyor,  and  the  other  an  endless  chain  of 
buckets.  (See  111.  Nos,  19,  20,  21.)  Usually,  the  Bucyrus  dredges, 
and  other  makes  except  the  Risdon,  are  equipped  with  belt  conveyors, 
while  the  Risdon  is  equipped  with  bucket  conveyors.  The  belt  con- 
veyor will  not  work  at  a  higher  grade  than  18  or  20  per  cent,  while  the 
bucket  conveyor  works  usually  at  35  degrees.  The  belt  of  the  former 
must  be  renewed  every  six  or  nine  months.     This  makes  the  cost  of 


GOLD  DREDGING  IX  CALIFORNIA. 


33 


''repairs"  considerably  more  than  for  the  bucket  conveyor.  However, 
to  otl'set  this,  there  is  considerably  less  loss  of  time  with  the  belt  con- 
veyor from  this  cause,  for  practically  the  only  wearing  part  is  the  belt, 
and  when  this  wears  out,  a  new  one  can  be  put  in  in  a  few  hours.  Some 
of  the  tables  of  loss  of  time  and  cost  of  repairs  of  conveyor  give  figures 
so  that  comparisons  can  be  made,  but  hardly  enough  data  have  lieen 
kept  to  figure  closely  on  the  dififerenees. 


ILL.  No.  20.     TAILINGS  STACKER.  BUCKET  CONVEYOR. 


In  New  Zealand  a  number  of  dredges  equipped  with  centrifugal 
stackers  are  in  use.  It  is  claimed  for  them  that  the  original  cost 
is  less,  that  the  weight  saves  several  tons  on  the  boats,  that  the  cost 
of  repairs  is  less,  and  that  the  efficiency  is  as  great  as  for  the  belt 
and  bucket  conveyors.  However,  none  have  been  built  in  California 
and  no  definite  data  are  at  hand. 


]LL    No    21.      CONTlXrtH'S-BUCKET    STACKING    LADDER    ON    "  KL    DoKAUO    No. 
DRIVEN   BY   INDEPENDENT  MOTOR   IN   SMALL   MOTOR   HOUSE    ON   TOP   OF 
LADDER.      LATEST    TYPE    RISDON    DREDGE 


ILL.  No.  22.     INDIANA  No.  1,  OKi)\lI>LK,  SHEWING  SAND  PIMP  \VORKIN( 


GOLD  DREDGIXG  IN  CALIFORNIA.  35 

Sand  Pumps.— In  order  to  prevent  the  filling  up  of  the  basin  in 
which  the  dredge  floats  and  eonseqnent  interference  with  its  flotation, 
in  many  cases  at  Orovilie  it  has  been  found  necessary  to  pump  the 
fine  tailings  that  come  from  the  sluice-box  up  to  the  top  of  the  rock 
pile  made  by  the  stacker  (see  111.  No.  22).  As  this  recpiires  considerable 
power,  it  is  discarded  wherever  possilile.  In  deep  ground  with  deep 
water,  it  is  not  required. 


SCREENS,  SLUICES,  ETC. 

The  conditions  that  are  most  important  to  be  considered  in  order  to 
■determine  the  kind  of  appliances  to  use  in  saving  the  values  are:  (1) 
Size  of  particles  of  gold;  (2)  Shape  of  the  particles,  whether  nuggety 
or  flaky;  (3)  Presence  of  clay:  (4)  Will  the  gold  amalgamate  readily; 
(5)  Amount  of  black  sand;  (6)  Amount  of  platinum;  (7)  Hardness 
of  gravel. 

Screens.  — Two  kinds  of  screens  are  used  in  California:  the  shaking 
and  the  revolving.  The  purpose  is  to  disintegrate  the  gravel  and 
clay  in  order  to  permit  the  fine  material,  the  values  and  water  to  pass 
through  the  holes  along  the  length  of  the  screen  to  the  gold-saving 
tables  or  sluices  below,  and  convey  all  coarse  material  to  the  stackers, 
to  be  carried  to  the  dump  piles.  As  to  screens,  two  main  questions 
must  be  determined:  {a)  Whether  to  use  a  revolving  or  a  shaking 
screen;    (6)   Size  of  holes  in  the  screen. 

As  to  (a),  the  hardness  of  the  gravel  and  the  presence  or  absence 
of  clay  are  the  main  determining  features.  If  the  gravel  is  a  clean 
wash,  comparatively  free  from  clay,  such  as  that  at  Orovilie  and  Fol- 
som,  the  shaking  screen  is  generally  preferred  to  the  revolving  screen, 
mainly  because  the  first  cost  and  the  cost  of  repairs  are  less.  How- 
ever, there  are  cases,  even  in  these  districts,  when  some  hard  pieces  of 
gravel  are  not  disintegrated  and  the  values  lost.  In  case  there  is  any 
•clay  present,  it  will  adhere  to  the  gravel  or  pieces  of  bedrock,  especially 
if  blocky,  or  will  "ball  up"  and  so  carry  off  the  gold.  In  a  shaking 
screen,  bowlders  and  larger  pieces  of  bedrock  will  not  be  turned  over 
so  that  the  water  jets  will  have  free  play.  This  is  the  case  especially 
in  such  bedrock  as  most  of  that  along  the  Yukon,  which  is  often  blocky, 
and  carries  much  gold  in  clayey  seams  down  to  a  depth  of  from  one  to 
six  feet.  Where  the  gravel  is  hard,  it  has  little  opportunity  to  disin- 
tegrate in  the  length  of  the  shaking  screen.  A  revolving  screen  with 
fi-anges  and  rods  across  the  screen  will  turn  the  material  over  and  over, 
subjecting  all  sides  of  it  to  the  force  of  the  water  from  the  jets,  and 
v\'ill  afiford  a  sort  of  milling  process  by  which  the  bowlders  and  smaller 


38  noT.D  nuKDaiNO  ix  cat-ifornma. 

stones  arc  lifted  iii)  and  thrown  down  on  \\w  ]uiii[)s  of  gravel  and 
clay. 

Under  the  favorable  conditions  existing  in  the  Sacramento  Valley 
districts,  the  shaking  screen  is  preferred  for  the  following  reasons: 
(1)  The  effective  screening  surface  is  larger;  (2)  It  is  easier  kept 
in  repair,  because  the  plates  are  small  and  conveniently  replaced; 
(3)  The  gravel  drops  over  a  larger  surface  on  the  plates  below,  and 
so  comes  the  better  in  contact  vv^ith  the  quicksilver.  Then  the  water 
from  the  jets  playing  down  on  the  screen  plays  over  a  wider  and 
thinner  surface. 

In  some  cases,  a  combination  of  the  revolving  and  shaking  screeois 
would  be  preferred.     In  this  way  two  screenings  could  be  had. 

The  revolving  screen  varies  in  diameter  from  3I/2  feet  and  in  leng-fli 
up  to  24  feet.  The  shaking  screen  for  a  5-foot  bucket  dredge  is  in 
some  of  the  later  dredges  built  in  two  parts— the  first  part  7  feet  wide 
and  16  feet  long,  and  the  second  or  lower  part,  7%  feet  wide  and 
16  feet  long.  This  enables,  of  course,  a  much  larger  sluicing-table 
space  to  be  employed  below  the  shaking  screen. 

The  size  of  the  holes  in  the  screens  will  be  determined  by  the  size 
of  the  largest  particles  of  gold.  At  Oroville  aiid  other  districts  in  the 
Sacramento  Valley,  where  all  the  gold  is  fine,  five-sixteenths  and 
three-eighths  inch  holes  are  generally  used.  Where  there  is  both 
coarse  and  fine  gold,  it  must  be  remembered  that  with  the  larger 
holes,  coarse  material  will  have  to  be  sluiced,  a  greater  depth  of  water 
will  be  required  in  the  sluices,  and  there  will  be  a  consequent  greater 
loss  of  fine  gold.  To  obviate  this,  it  is  suggested  that  smaller  holes 
be  used  in  the  upper  part  of  the  screen  and  larger  holes  in  the  lower 
part,  and  that  the  finer  and  coarser  material  be  run  into  separate 
sluices.  It  would  not  be  necessary  to  have  the  larger  holes  in  more 
than  four  feet,  or  even  less,  of  the  length  of  the  screen. 

Sluices.  — On  the  dredges  in  the  Sacramento  Valley  districts,  such  as 
Oroville,  Yuba,  and  Folsom,  the  gold  is  saved  on  what  are  called 
gold-saving  tables  (see  111.  Nos.  2-1  and  25)  and  a  sluice  running 
out  astern  of  the  dredge  where  the  tailings  are  dumped  into  the 
water.  The  area  of  these  tables  is  for  a  5-foot  dredge  with  shaking 
screen  about  750  square  feet  and  for  the  sluices  about  300  square  feet, 
and  somewhat  less  with  revolving  screens.  This  area  is  somewhat  less 
for  the  smaller  dredges  and  more  for  dredges  of  larger  capacity.  As 
it  is,  generally  speaking,  all  the  surface  possible  is  made,  and  it  is 
limited,  of  course,  to  the  size  of  the  boat.  There  can  be  no  question 
but  that  much  of  the  finer  gold  is  lost.  How  much  this  may  be  has 
not  been  determined,  for,  no  matter  haw  careful  the  rocking  and  pan- 
ning of  the  drill  samples,  the  finest  gold  is  not  saved. 


40  GOLD  DREDGING  IN  CALIFORNIA. 

It  may  be  said  that  if  some  of  the  finest  gold  saved  at  Oroville  were 
shaken  vip  in  a  bottle  of  clear  water  it  will  take  two  hours'  time  to 
settle  again.  Therefore,  neither  panning,  nor  rocking,  nor  any  of  the 
present  gold-saving  devices  can  save  all  the  gold.  One  of  the  best 
informed  men  at  Oroville,  who  has  been  in  the  industry  since  the 
beginning,  says  that,  with  the  improvements  that  may  in  time  be  made 
in  the  gold-saving  appliances,  it  would  be  possible  to  save  more  gold 
in  the  dredges  than  could  be  shown  by  the  most  careful  and  exact 
sampling  with  pans  and  rockers. 

In  most  cases  at  Oroville  and  Folsom,  the  tailings  are  sampled  in 
order  to  determine  how  much  gold  is  being  lost.  But  this  sampling  is 
of  no  value  except  to  show  that  the  sluice-boxes  and  tables  save  a 
large  per  cent  of  what  could  be  found  by  panning  or  rocking.  In 
other  words,  very  little  is  found  in  the  tailings,  and  in  most  cases 
practically  none  at  all,  by  panning  or  rocking. 

The  quantity  of  fine  gold  which  goes  off  in  the  water  should  be 
determined  by  test,  and  if  it  amounts  to  as  much  as  seems  probable, 
there  should  be  devised  a  scheme,  in  connection  with  the  sand  pump, 
for  an  auxiliary  saving  appliance  that  would  enable  a  larger  propor- 
tion of  the  finest  gold  to  settle.  The  amount  of  extra  power  that  would 
be  required  and  the  cost  of  extra  equipment  need  not  be  much.  Of 
course,  the  larger  the  dredge,  the  greater  the  opportunity  to  save  larger 
proportions  of  the  gold  now  being  lost. 

There  are  two  classes  of  sluice  and  table  paving  used  in  the 
Sacramento  Valley  gravels  to  save  the  fine  gold.  ,  One  is  ordinary  Hun- 
g'arian  or  cross  riffles  with  quicksilver,  and  the  other  cocoa  matting 
covered  with  expanded  metal,  2yo-incli  mesh.  These  are  nearly 
equally  satisfactory,  so  far  as  the  managers  report.  However,  in 
most  cases  each  manager  has  used  only  one  kind  and  made  no  compar- 
ison. Where  comparison  has  been  made,  the  preference  seems  to  be 
in  favor  of  the  riffles  with  quicksilver.  There  is  no  arsenic  or  any- 
thing else  present  to  prevent  a  rather  free  amalgamation.  Yet  there 
is  present  so  much  black  sand  which  would  prevent  the  gold  from 
reaching  the  quicksilver  that  it  is  found  necessary,  in  putting  in  the 
riffles,  to  insert  between  them  stones  that  stand  up  above  the  tops 
of  the  riffles  in  order  to  stir  up  the  black  sand  and  allow  the  gold 
to  go  to  the  bottom.  On  the  cocoa  matting,  the  expanded  metal,  in 
diamond  shape,  about  one-fourth  iivth  deep,  is  placed  for  the  same 
purpose. 

One  of  the  most  careful  managers  at  Oroville  states:  "We 
originally  used  cocoa  matting  on  our  dredge,  but  later  installed  the 
riffles  and  quicksilver  and  increased  our  gold-saving  area  85  square 
feet,  by  utilizing  the  space  in  the  distiiibuting  box  directly  under  the 


GOLD  DREDGING  IN  CALIFORNIA.  41 

screen.  We  are  going  to  ii.se  riffles  and  quicksilver  in  our  new 
dredge. ' ' 

Under  the  screens  on  the  first  tables  quicksilver  in  large  quantities 
held  in  place  by  riffles  is  used  with  a  view  to  bringing  the  fi-ne  gold 
into  contact  as  it  drops  from  the  screens.  In  this  respect,  shaking, 
screens  do  better  work  than  revolving  screens,  because  they  let  the 
fine  material  down  over  a  larger  surface. 

Both  at  Oroville  and  Folsom,  and  even  at  Yuba,  it  has  been  found 
that  gold— even  the  very  finest  gold— if  brought  in  contact  with  the 
quicksilver  will  amalgamate  without  much  difficulty.  In  Colorado 
and  in  Idaho,  where  there  is  fine  gold,  and  dredging  has  been  done 
on  rather  an  extensive  scale,  it  has  been  found  impossible  to  make  any 
consequential  saving  of  gold  vdth  quicksilver,  owing  to  the  presence 
of  arsenic  or  something  else.  The  result  is  that  cocoa  matting  or 
some  similar  appliance  must  be  used.  It  would  appear  that  where 
the  very  fine  gold  amalgamates  freely,  riffles  and  quicksilver  are 
preferable  to  cocoa  matting. 

As  platinum  does  noit  amalgamate  with  quicksilver,  there  is  a 
greater  loss  of  this  metal  when  riffles  and  quicksilver  are  used,  than 
when  cocoa  matting  and  expanded  iron  mesh  are  used. 

CREW  OF  A  DREDGE. 

The  following  table  will  give  an  idea  of  the  number  of  men 
commonly  rec|uired  on  dredges.  The  Avages  named  are  those  usually 
paid  at  Oroville : 

Crew  for  One  Dredge.  Per  Day. 

1  foreman,  at  .fo.W  per  day |o  00  —  $5  00 

3  winchmen,  at  $3.00  to  .IS.oO  per  day 9  00  —  10  50 

Sellers,  at  $2.00  to  .|2.50  per  day 6  00  —    7  50 

1  blacksmith,  at . 13.50  per  day 3  50  —    3  50 

1  helper,  at  $2.00  to  $2.50  per"  day e 2  00  —    2  50 

2  Chinamen,  at  $1.75  to  $2.50  per  day 3  50  —    5  00 

Total .. $29  00  — $:34  tX) 

In  addition  there  is  a  superintendent,  whose  time  is  generally 
divided  among  several  dredges.  The  winchmen  and  oilers  work  eight- 
hour  .shifts,  while  the  blacksmith  and  helper  work  ten  hours.  The 
Chinamen  clear  the  ground  of  brush  and  trees,  "bury  dead  men," 
as  making  fasteners  for  the  lines  is  called,  and  do  general  chores. 

The  depth  to  which  the  present  dredges  may  dig  is  from  30  to  60 
feet  below  the  water-level,  the  latter  depth  being  reached  by  the 
new  dredges  on  the  Yuba.  That  greater  depths  may  be  reached  is 
only  a  question  of  increased  strength  and  power  and  longer  digging 
ladders.  These  work  at  their  best,  it  is  claimed,  on  an  angle  of 
45  desrrees. 


42  GOLD    DREDGING    IN    CALIFORNIA. 

WORKING  COSTS. 

A  majority  of  the  dredge  companies  in  California  have  given 
statements  as  to  the  approximate  actual  cost  of  dredging  per  cubic 
yard,  which  will  be  found  in  the  accompanying  folder,  and  in  tables 
following.  These  costs  vary  from  2.36  and  3  cents  to  as  much  as  81/2 
cents.  It  will  be  seen  that  where  a  return  of  3  cents  or  less  is  given,  it 
is  for  a  new  dredge  with  all  the  advantages  of  the  latest  ideas  as  to 
strengthening  the  parts  of  the  machinery,  and  that  there  have  been 
no  breakdowns  and  consequently  very  little,  if  any,  costs  for  repairs. 
The  labor  bill  has  been  very  light,  for  the  running  time  has  been  full. 
The  owners  of  this  dredge  have  stated  that  their  costs  will  be  mate- 
rially increased  in  working  longer  periods  of  time,  through  the  loss  in 
actual  Avorking  time  caused  by  breakdowns  and  the  cost  of  new  parts 
and  for  repairs. 

So  it  is  only  those  reports  on  dredges  which  have  been  in  operation 
for  a  long  time,  say  three  or  four  years  at  least,  that  are  of  much  value 
in  determining  what  would  be  the  average  cost  of  woi'king  under  sim- 
ilar conditions.  However,  one  must  remember  that  the  lately  built 
dredges  are  more  strongly  made  and  afford  less  opportunity  for  break- 
age and  repair  costs.  The  record  for  low  cost  is  2.36  cents  per  cubic 
yard  with  a  new  dredge,  as  will  be  noticed  in  the  tables  of  cost  given 
elsewhere  in  this  bulletin. 

In  studying  these  reports,  one  must  consider  in  respect  to  the 
different  districts:  (1)  The  cos't  of  power;  (2)  The  rate  of  wages; 
(3)  Whether  the  company  reporting  has  one  or  several  dredges  under 
one  management;  (4)  Whether  the  company  has  its  own  machine 
shop  or  not;  (5)  The  hardness  of  the  ground,  and  this  particularly 
as  to  whether  blasting  with  powder  is  necessary;  (6)  The  size  of  the 
buckets;  (7)  Whether  the  buckets  are  alternating  or  close-connected; 
(8)  Whether  belt  or  bucket  conveyor  is  used;  (9)  Whether  revolving 
or  shaking  screens  are  used;  (10)  Whether  a  sand  pump  is  used; 
(11)   The  age  of  the  dredge. 

Only  one  company  operating  at  Folsom  returns  cost  of  working, 
and  that  at  5  cents.  At  Folsom  the  cost  for  power  is  0.65  of  a  cent 
per  kilowatt  hour,  while  at  Oroville  it  is  1%  cents. 

Some  idea  of  the  difference  in  cost  per  cubic  yard  between  operating 
one  dredge  and  operating  several  dredges  under  one  management  may 
be  had  from  the  estimate  of  the  Oroville  Gold  Dredging  and  Explora- 
tion Company,  and  this  comparison  table,  showing  the  estimated  cost 
of  one  or  three  dredges,  all  under  one  management.     (See  tables.) 

Of  course,  under  certain  difficult  conditions  a  dredge  of  small 
capacity  may  be  preferable,  but  under  most  ordinary  conditions,  such 
as  at  Oroville,  Folsom,  and  other  places  in  the  Sacramento  Valley, 


44 


GOLD  DREDGING  IN  CALIFORNIA. 


the  greater  the  yardage  capacity  of  the  dredges,  the  lower  the  cost  of 
working. 

It  may  be  said  that  the  cost  of  repairs  is  still  excessive,  but  this 
item  of  expense  has  been  reduced  from  year  to  year  since  the  first 
successful  dredge  was  put  in  operation  in  1898.  It  may  be  said,  too, 
that  if  the  dredge-builders  had  not  increased  the  strength  of  the 
buckets,  the  quality  of  steel  used,  and  in  many  other  ways  strength- 
ened all  the  straining  and  wearing  parts  of  the  dredges,  it  would  now 
be  impossible  to  build,  as  they  propose  doing  at  Folsom,  a  dredge  with 
13  cu.  ft.  buckets,  or  even  7  cu.  ft.  buckets.  A  comparison  of  costs  of 
a  new  dredge  with  those  of  an  old  dredge  of  the  same  size  and  type 
is  therefore  unfair. 

Whenever  the  Bucyrus  type  of  dredge  is  mentioned,  it  is  under- 
stood to  have  close-connected  buckets,  a  shaking  screen,  belt  conveyor, 
and  riffles  and  quicksilver  on  the  sluicing-tables ;  while  the  Risdon 
,dredge  has  alternating  buckets  and  links,  a  revolving  screen,  bucket 
conveyor  and  cocoa  matting,  with  expanded  metal  mesh  covering 
them  on  the  sluices.  It  may  be  said,  however,  that  the  makers  provide 
for  the  mine  owners  whatever  style  of  any  of  these  parts  they  may 
require. 

It  is  for  the  dredge-builders  and  for  the  skilled  managers  at 
Oroville  or  Folsom  or  elsewhere  in  the  State  to  more  seriously  consider 
this  question  of  cost  of  repairs  than  anything  else,  except,  of  course. 
the  question  of  saving  the  present  loss  of  fine  gold,  w^hich  is  far 
greater  than  most  of  them  suppose. 

The  following  tables  (Nos.  1  to  8)  are  from  the  annual  report  of 
the  Oroville  Gold  Dredging  and  Exploration  Company  of  San  Fran- 
cisco, for  the  calendar  year  1903 : 

TABLE  No.  1-BULLION  TABLE. 

^  ^  . 

Cubic  Yards  |   Cost 

Tvf„„.i,  (BankMerts-  Operating         per 

uremeiit)  PLxpenses.      ;  Cubic 
Dredged.  |  Yard. 


January .. 
February  _ . 

March 

April 

May 

June 

July 

August 

September. 

October 

November. 
December . 


Totals  and  averages. 


*31,000 
*30,130 
*3(l,570 
49,130 
35,900 
34,040 
40,100 
46,000 
4(;,790 

r)(),9tio 

39,420 
40,570 


474,610  1  $30,784  95 


,712  77 
,804  48 
,895  99 
,684  32 
,273  46 
,667  87 
,017  13 
,884  83 
,529  99 
,574  56 
,530  64 
,208  91 


CenU. 
5.52 
5.98 
9.47 
5.46 
6.33 
7.83 
7.52 
8.44 
5.34 
5.05 
6.42 
5.45 


6.48 


*Iii  January,  February,  and  March,  44,080  cubic  rards  of  soil  were  dredged  on  moving  dredge 
to  block  1%. 


i  > 


:_  o 


46 


Cost  per 
Yard.... 

|S= 

GOLD 

DREDGING   IN    CALIFORNIA, 

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GOLD  DREDGING  IX  CALIFORXIA. 


47 


Table  Xo.  2  does  not  include : 

Bullion  expense 04 

Taxes  and  insurance 38 

San  Francisco  general  expenses .17 

A  total  of  0.59  to  be  added  to  make  up  the  total  of  the  summary  of 
costs  in  cents  per  cubic  yard,  in  Table  Xo.  4. 


TABLE  No.  3— EXTRACTION  TABLE. 


Ii:l 


O, 


J^    S:'   Character  of  Ground 
f  Dredged. 


January  . 
February 
March  .__ 


i!26.7G.     0.49  G. 
"»:14.7S.      0.43  S. 


14.5  S. 
14.0  S. 
27.2  G. 
28.6 

28..5 


April 

May 

.Tuiie 

July 

August UA 

September 30.0 


1.29  8. 

0.18  S. 

0.59  G. 

1.06 

0.78 

0.69 

0.68 

0.78 

0.96 


20,8.50  G.  ( 

10,1.5US.    (" 

30,130  S.    .. 
4.400 S.    » 

26,170  G.  s 

49,130 
j  35,900 

34,G10 

40.100 

46,000 
!  46,790 


pr.  ct.   Cents,  o    •  i        i    •    i 

58     5  5''  ^       tight  gravel 
■  "        containing  clav. 
5.98  Soil. 


ri     9.47 


joil  and  loose  gravel. 


October 30.7       |   1.03      j  50,960 

November 28.1       '  0.87      '  39,420 

December 26.7  0.94        40..570 


Totals  and  averages   30.4 


2  I  173 
2  105 
1         124 


5.46  Soil  and  loose  gravel. 

6.33  Soil  and  loose  gravel. 
7.83  Soil  and  loose  gravel. 
7..52  Soil  and  loose  gravel. 

8.44  Soil  and  loose  gravel. 

5.34  Soil  and  loose  gravel. 

worked  by  Chinese. 

5.05  Sand  and  fine  gravel. 

6.42  Sand  and  fine  gravel. 

5.45  Some  Chinese  tail- 
ings. 


48 


GOLD  DREDGING  IN  CALIFORNIA. 


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50 


GOLD  DREDGING  IN  CALIFORNIA. 


Aveiago  Amnuiil 
Dredged  per  Day 
of  2-lHours 


Average  Amount 
Dredged  per  Day 
of  K  u  n  n  i  II  g 
Time 


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Time 


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S  in  e  >> 

S     S      ''i      ^  ■ 


<1     cc     O     ^     P 


GOLD    DREDGING    IN    CALIFORNIA.  51 

TABLE  No.   7— SUMMARY  OF  COST,   1903. 

(In  ct'iits  per  cubic  yariL) 

One  Dredge.  Three  Dredges. 

Dredge  crew,  power,  and  operating'  sui»plies.._ 2.52  2.52 

Repairs^-Lahor .98  .48 

Supplies 2.65  2.58 

Total  operating  costs 6.10  5.58 

Superintendence .38  .16 

General  expense— Oroville .28  .09 

San  Francisco .17  .06 

Ta xes  and  insurance .38  .24 

I'ullion  expense .04  .04 

(Jrand  total  all  costs 7.35  6.17 

The  cost  for  the  same  dredge  for  91/0  months  in  1904  (January  1 
to  October  15)  was: 

Amount  dredged  (bank  measurement) .'._-  .378,890  cu.  yds. 

Cost  per  cubic  yard — 

Alllabor  __.. 2.82  cents 

Power 1.01  cents 

All  supplies 1.88  cents 

Total 5.71  cents 

This  does  not  include  about  0.59  of  a  cent  to  be  added  for  general 
expenses,  which  would  bi-ing  the  total  up  to  6.30  cents,  as  against  7.35 
cents  for  1903. 

The  above  work  was  done  with  one  5  cu.  ft.  bucket,  close-connected 
Risdon  dredge,  with  revolving  screen  and  bucket  conveyor.  It  was 
the  intention  of  the  company  to  build  two  more  dredges.  However, 
one  larger  dredge  is  now  being  built,  with  the  view  of  handling,  with 
the  two,  100,000  cubic  yards  per  month,  at  a  cost,  as  estimated,  of  5.71 
cents  per  cubic  yard. 


52  GOLD  DREDGING  IN  CALIFORNIA. 

Since  the  above  was  written  a  record  has  been  made  with  the  new 
Bucyrus  dredge,  "Biggs  No.  2,"  of  the  Oroville  Gold  Dredging  and 
Exploration  Company,  which  shows  a  cost  considerably  below  any 
other  similar  work  in  the  State,  as  far  as  known.  In  tabulated  form 
the  results  are  shown  as  follows : 

TABLE  No.  8~REC0RD  OF  NEW  BUCYRUS  DREDGE,  BIGGS  No.  2. 

For  31  Days,  from  For  30  Days,  from 

February  26  to  March  April  1  to  April  30, 

30,  1905,  inclusive.  1905,  inclusive. 

Possible  dredging  time 31  days  30  days 

Lost  time 119  hours  18  min.  149  hours  55  min. 

Average  actual  dredging  time  per  day 20  hours  9  min.  19  hours  00  min. 

Total  amount  dredged  (bank  measurement) 102,630  cubic  yards  109,630  cubic  yards 

Amount  dredged  per  day 3,310  cubic  yards  3,654  cubic  yards 

Operating  costs  per  cubic  yard- 
All  labor 1.16  cents  .82  cents 

Power ....  .      .39  cents  .82  cents 

All  supplies .81  cents  .37  cents 

Other  expenses _(__.    ..   ...  1.34  cents 

Total 2..36  cents  3.35  cents 

As  to  the  two  following  tables  from  Oroville  companies,  the  general 
manager  says:  "We  have  not  been  running  the  Bucyrus  machine  a 
j'^ear's  time  in  ordinary  diggings,  and  I  am  obliged  to  send  you  a 
record  of  our  machine  of  the  Bucyrus  type  which  has  been  running  in 
very  extraordinary  ground,  and  some  of  the  heaviest  digging  in  the 
Oroville  district.  This,  of  course,  decreases  the  capacity  of  the  machine 
and  increases  the  cost  of  handling,  but  it  is  just  as  w^ell  to  have  some 
data  from  the  harder  places  as  to  have  all  conditions  favorable,  espe- 
cially for  general  information  that  might  lead  to  investment. ' '  In  this 
case  the  use  of  powder  increased  the  cost. 

It  will  be  noted  that  the  Risdon  dredge  has  open-connected  buckets 
and  a  bucket  conveyor,  while  the  Bucyrus  has  close-connected  buckets 
and  a  belt  conveyor. 


54 


GOLD  DREDGING  IN  CALIFORNIA. 


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GOLD  DREDGING  IN  CALIFORNIA. 


The  follo^ving  table  of  costs  applies  to  a  3I/2  cu.  ft.  close-connected 
bucket  line  dredge.  For  the  first  month  the  cost  was  increased  by 
expense  of  organization  and  management  prior  to  commencement  of 
operations,  the  company  proposing  to  place  under  the  head  of  cost 
of  operating  all  expenses  (including  insurance,  taxes,  and  office)  except 
the  original  cost  of  the  ground  and  the  dredge.  In  April,  the  high 
water  caused  a  shutdown.  An  entire  new  bucket  line  purchased  and 
on  hand,  and  a  40-horsepower  motor  to  replace  the  first  motor  of 
30-hor.^epower  for  the  pump,  considerably  increased  the  cost. 

TABLE  No.  11. 


Cubic  Yds. 
(Bank  Meas- 
urement) 
Dug. 

Per  Cent 
of  Time 
Operated. 

Cost  per  Cubic  Yard. 

1903. 

Labor. 

Power. 

Repairs 

and 
Supplies. 

General 
Expense. 

Total 
Expense. 

December 

January  

February  

March 

April 

May 

35,000 
37,000 
37,800 
40,500 
24,680 
33,572 
44,878 
35,520 
49,340 
34,226 
36,000 
38,000 
38,500 

68.78 
67.61 
86.16 
65.88 
42.68 
74.33 
87.76 
72.44 
84.80 
88.99 
88.68 
88.43 
86.73 

cents. 
3.82 
3.06 
2.76 
2.50 
3.92 
3.22 
2.34 
3.15 
2.35 
3.05 
2.97 
2.70 
2.85 

cents. 
2.21 
1.73 
1.99 
1.81 
1.70 
2.38 
1.75 
1.96 
1.31 
1.90 
2.29 
1.99 
1.75 

cents. 
1.30 
2.76 
1.14 

.38 
4.14 
3.70 
2.39 
2.80 
3.35 
2.85 
2.07 
4.33 

.87 

centfi. 

3.98 
.23 
.62 
.28 
.35 
.16 
22 
".18 
.10 
.32 

3.19 
.26 
.17 

0.75 

cents. 

11.36 
7.78 
6.51 
4.87 

10.10 
9.46 

July 

8  10 

August 

September 

October 

November 

December 

7.11 
8.12 
10.52 
9.28 
5.63 

Average  per  mo. 

37,309 

77.11 

2.91 

1.89 

2.41 

7.96 

The  following  table  of  loss  of  time  is  for  the  same  dredge  during 
the  first  twenty-two  months  of  working  from  December  1,  1902.  The 
figures  are  averages  of  hours  lost  per  month: 

TABLE  No.    12. 

Cause  of  Stoppage.  Hours.  Per  Cent. 

Stepping  ahead 11.29  8.1 

Ladder  and  bucket  line 34.60  24.9 

Stacker 5.80  4.1 

Winches . 2.90  2.1 

Screen 6.20  4.5 

Water  pump .56  .4 

Sand  pump 5.40  3.9 

Lines 2.40  1.7 

Power . 26.00  18.7 

Other  causes 36.20  26.0 

Clean-up 7.80  5.6 

Total 139.15  100.0 

In  addition  there  was  lost  some  time  while  the  power  was  off,  and 
some  through  floods.  The  average  amount  of  material  handled  for  the 
twenty-two   months  was   39,900   cubic   yards   per   month.     The   main 


GOLD  DREDGING  IN  CALIFORNIA. 


57 


saving  in  time  was  made  by  putting  new  eastings  in  the  bucket  line 
early  in  1904. 

The  following  figures  of  costs  are  for  a  new  3  cu.  ft.,  close-connected 
bucket  dredge,  with  shaking  screen  and  belt  conveyor,  at  Oroville. 
They  show  how  costs  increase  as  parts  wear  out.  These  expenses 
include  office,  secretary,  and  all  expenses  in  full: 


TABLE 

No.   13. 

December  1, 1902,  to 
June  1, 1903. 

June  1, 1903,  to 
June  1,  1904. 

227,868  cu.  yds. 
37,978  cu.  yds. 

78% 

437,441  cu.  yds. 

36,454  cu.  yds. 

Per  cent  of  workina'  time 

76% 

Total 
Expense. 

Cents  per 
Cubic  Yd. 

Total 
Expense. 

Cents  per 
Cubic  Yd. 

Payroll 

$5,001  93         2.195 

4,760  49         2.089 

772  18  j         .340 

400  02            .176 

998  90  1         .438 

1,166  43           .512 

$10,421  86 
8,861  90 
1,367  55 
1,297  15 
1,920  57 
8,033  76 

2.382 

Power 

Dredge  supplies 

Taxes  and  insurance 

Sundry  expenses 

Maintenance  and  repairs 

2.026 
.313 
.297 
.439 

1.836 

Total  cost 

$13,099  95 

5.75 

$31,902  79 

7.293 

The  following  figures  are  from  the  report  made  to  an  Oroville 
company  for  the  year  1903,  of  a  dredge  that  began  operations 
November,  1902.  The  bucket  capacity  is  5  cubic  feet,  close -connected, 
shaking  screen.s  and  belt  conveyor: 

TABLE  No.   14. 

Working  days  in  year __- 363 

Working  hours  in  year -. 8,712 

Power  was  off — hours 389.66 

Possible  working  hours --- ---  8,322.33 

Total  hours  machine  was  digging  through  year 5,710.58 

Percentage  of  total  hours  digging -. . 65.5 

Percentage  of  possible  hours  digging 68.6 

Surface  area  worked  out— acres 13.297 

Average  depth  of  cut 24.55 

Cubic  yards  handled 526,680 

Cubic  yards  handled  per  day — .-.- 1,450.909 

Cubic  yards  handled  per  digging  day 92.228 

Cents  per 

Cost  of  Dredging-  Cubic  Yd. 

For  labor 2.593 

For  power 1-744 

For  supplies -441 

For  shop  repairs  and  parts -.  2.360 

For  freight  , .162 

For  general  expense  and  boarding-house  loss. .-  .142 

For  clearing  land-. -156 

Tofal  cost  at  dredge --. 7.598 


;-),S  GOLD  DREDGING  IN  CALIFORNIA. 

Tot-il  Cents  per 

Other  Costs  (Administration,  Taxes,  Insurance,  etc.)—  Expense.  Cubic  Yd. 

San  Francisco  office,  management  and  traveling  expenses...     .$4,229  6t)  0.803 

Treasurer's  office  expense 87  9!i  .017 

Taxes - 663  15  .126 

Insurance 529  75  .100 

Total  administration,  etc $5,510  55  1.046 

Add  costs  at  dredge,  as  above 40,033  14  7.598 

Total  costs,  all  included .|4.5,543  69  8.644 

The  following  gives  the  cost  from  January  1  to  September  30,  1904 
(nine  months),  of  a  5  en.  ft.  connected  bucket  Risdon  dredge,  Avith 
bucket  conveyor,  at  Oroville.  As  the  company  operates  five  dredges, 
some  of  the  costs  are  less  than  they  would  be  for  one  dredge  under  one 
management : 

TABLE  No.   15.  Cents  per 

Total.  Cubic  Yd. 

Power 13,116  35  .8796 

Labor  operating , 5,016  04  1.41.57 

Supplies 90  13  .0254 

Repairs 9,623  63  2.7161 

Office 1,036  47  2925 

Incidental 874  31  .2468 

Teaming 1 ■... 276  56  .0781 

.i;20,0.33  49  5.6542 

Total  number  of  hours  run,  5,100. 
Total  number  of  cubic  yards  dredged,  354,311. 

Tlie  following  table  gives  the  cost  of  operating,  for  the  first  six 
months,  Leggett  No.  3— a  new  Risdon  5  cu.  ft.,  open-connected  bucket 
dredge,  with  revolving  screen  and  bucket  conveyor. 

This,  of  course,  is  the  case  of  a  new  dredge,  where  the  cost  of  repairs 
and  replacing  of  parts  has  been  very  light;  it  amounts  to  not  more 
than  one  fourth  of  the  repaire  of  a  similar  dredge  worked  by  the 
Oroville  Gold  Dredging  and  Exploration  Company — an  older  dredge, 
however,  and  probabh^  not  as  strongly  constructed  as  was  this. 

TABLE  No.   16. 

Total  quantity  of  ground  handled ...  .315,165  cu.  yds. 

Average  depth  of  ground ...  ,30  feet. 

Cost  of  power,  at  IJ  cents  K.  W.  hour |4,241  97 

Cost  of  labor 4,250  (Kt 

Cost  of  management 900  00 

Cost  of  water 450  00 

Cost  of  repairs ^ 1,929  37 

Cost  of  supj)lies 722  42 

Total  cost . 112,493  76 

Average  running  time  per  day,  20  hours  8  minutes.     Sufficient  lost. time  on  account 
of  lack  of  power  to  make  a  total  of  21  hours  per  day. 
Average  cost  per  cubic  yard,  3.94  cents. 

The  following  figures  are  taken  from  Mr.  L.  J.  Hohl's  paper,  read 
before  the  California  Miners'  Association.     He  states  that  they  will 


GOLD  DREDGING  IN  CALIFORNIA. 


59 


give  a  fair  representation  of  the  extremes  of  cost  per  cubic  yard  at 
Oroville : 

TABLE  No.  17. 

Power     l.Ofi  1.20  1.15  l.fiJ  1.77 

Repairs 2.86  3.03  3.4G  2.1)7  .3.80 

Labor.. LW  1.32  1.85  2.33  2.05 

Oeneral  expenses -W  .(i7  1.23  1.28  .73 

Total 6-20  <>.72  7.()!»  8.1!t  8.35 


In  the  following  case,  the  running  time,  on  the  basis  of  365  days 
in  the  year,  was  sixteen  hours  in  the  twenty-four.  It  Avill  be  observed 
that  a  large  percentage  of  the  loss  was  caused  by  floods  in  the  Feather 
River.  This,  of  course,  is  an  extreme  case.  The  figures  are  for  a 
5  cu.  ft.  close-connected  bucket  dredge.  The  tumbler  loss  was  owing 
to  not  having  tumblers  on  hand : 


TABLE  No.    18. 


Causes  of  Stoppage. 


Belting 

Bucket  line 

Lines  breaking,  and  changes 
Cleaning  up 


Per  cent 

l; 

23. 

-.__  4.i 
1. 

_-__  5. 


Conveyor 5.3 

Elevating  machinery 1.5 

Frictions  and  winches -.   2.5 

Oeneral  repairs 1-7 

High  water 15.6 

Holidays 1 1-8 

Ladder  and  ladder-hoist. 1-3 

Lower  tumbler — .-  8.3 


Oi 


3.8 


Power  off 4. 

Shaking  screen 4. 

Stones,  roots  and  stumps   0. 

Upper  tumbler -• 16. 

Water  pump 1- 


Total 


100, 


The  following  monthly  averages  are  given  as  one  year's  work  on 
three  Risdon  dredges  of  different  capacity,  but  all  with  alternate 
buckets,  revolving  screens,  and  bucket  conveyors: 

TABLE  No.   19. 


Average  Time  Run 
per  Month. 

Size  of 
Buckets. 

Age  of  Dredge  at 
End  of  Year. 

Cubic  Yds.  Dredged 
per  Month. 

Cost   per   Cubic 
Yard,  in  Cents. 

575  hours. 

3cu.  ft. 

5  years. 

31,666 

5.86 

538  hours. 

5  cu.  ft. 

3  years. 

46,032 

4.86 

558  hours. 

4  cu.  ft. 

18  months. 

28,207 

8.69 

60  GOLD  DREDGING  IN  CALIFORNIA. 


PROSPECTING  AND   EXAMINATION   OF  CONDITIONS. 

It  may  seem  a  simple  thing  to  say  that  a  careful  study  of  all  the  con- 
ditions should  be  made  before  a  dredge  is  ordered,  no  matter  how  large 
the  values  in  gold  may  he  found  to  be.  The  values  may  in  many  cases 
be  of  almost  minor  importance,  or  of  no  importance,  where,  as  is  the 
case  in  some  of  the  mountain  districts,  the  hardness  of  the  bedrock, 
with  much  of  the  gold  on  the  bedrock,  has  prevented  dredging  very 
rich  ground.  There  have  been  many  failures  in  California,  and  all 
because  proper  examination  of  the  ground  was  not  made  before  the 
dredges  were  built. 

In  Trinity  County,  in  one  case,  a  dredge  was  put  in  and  failed  and 
has  been  dismantled  because  the  fact  that  the  ground  was  valueless  was 
not  proved.  There  is  another  case  where  a  dredge  was  built  and 
operated  for  a  time  on  very  heavy  ground,  but  it  was  so  weak  in  con- 
struction that  it  failed  and  was  dismantled.  Now  another  company  is 
building  a  dredge  to  work  the  same  ground,  with  every  promise  of 
success.  There  are  similar  wrecks  in  the  Oroville  sea  caused  by  incom- 
petent pilots. 

It  has  been  said  in  regard  to  sampling,  that  which  will  apply 
to  any  other  part  of  the  examination  of  a  dredging  property:  "Hap- 
hazard and  occasional  sampling  and  assaying  are  worse  than  useless. 
They  lead  to  great  losses  of  valuable  capital,  frequently  to-  the  total 
abandonment  of  good  properties,  and,  worse  than  all,  to  a  false  sense 
of  satisfaction  that  discourages  improvement  by  denying  its  necessity. ' ' 

Conditions  to  he  Considered.— The  following  are  some  of  the  condi- 
tions, etc.,  to  be  determined  by  drilling  and  other  examination  prior 
to  determining  whether  the  ground  may  be  dredged,  prior  to  estimating 
costs,  and  prior  also  to  determining  the  kind  of  dredge  to  be  used: 

Value  iu  gold  por  culjic  yard,  and  its  dis-  Whether  l^edi-ock  is  level  or  not. 

tribution.  Water— amount  of  supply,  and  cost. 

Hardness  of  gravel.  Cost  of  power. 

Total  depth  of  gravel  to  bedrock.  Wages. 

Depth  of  gravel  from  water  level  to  bedrock.  Cost  of  transportation. 

Whether  level  or  rough  on  surface.  Cost  of  supplies. 

Size  of  bowlders.  Cost  of  repairs. 

Amount  of  clay  in  gravel.  Cost  of  land. 

Hardness  of  bedrock.  Climatic  conditions. 

Hardness  of  Gravel. — Generally  speaking,  any  gravel  that  may  be 
picked  may  be  dug  with  the  dredge,  without  the  use  of  powder.  If  it 
is  so  hard  as  to  require  blasting,  the  cost  per  cubic  yard  will  be 
increased  from  2  to  3  cents. 

Depth  of  Gravel.— The  most  satisfactory  depth  to  dredge  with  some 
of  the  newer  dredges  now  in  use  is  not  to  exceed  60  feet,  but  they  will 


J      -n 


GOLD  DREDGING  IN  CALIFORNIA.  61 

work  down  to  70  feet.  In  order  to  work  to  a  greater  depth  than  70 
feet,  some  changes  in  the  digger,  stacker,  and  power  would  be  required. 

Level  Surface  of  Gravel.— With  an  uneven  surface  the  use  of  head- 
lines is  not  so  satisfactory  as  spuds. 

Size  of  Bowlders. — Very  large  bowlders  can  not  be  handled  with  the 
ordinary  dredge,  and  much  gravel  may  be  left  on  the  ground.  The 
size  of  the  bowlders  must  be  considered  also  in  deciding  whether  to 
use  an  open  or  close  connection  of  buckets  in  the  digger,  the  latter 
rendering  it  impossible  to  handle  the  larger  bowlders. 

Climatic  Conditions. — Of  course,  freezing  weather  will  prevent  wash- 
ing the  gravel,  and  cause  a  stoppage  of  work.  In  the  northern  latitudes 
of  Montana  and  Alaska,  the  season  is  commonly  not  more  than  five 
months  long. 

Clay  in  Gravel. — The  clay  will  not  permit  of  clean  dumping  from  the 
buckets,  and  not  only  is  much  gold  carried  back  to  the  bottom  and  lost, 
but  the  yardage  capacity  of  the  dredge  is  decreased.  Besides  this,  the 
clay  carries  off  gold  and  fine  amalgam  from  the  sluice-boxes. 

Hardness  of  Bedrock.— li  the  bedrock  is  too  hard  to  dig,  gold  in 
the  crevices  or  lying  near  the  bedrock  is  lost.  The  drill  will  locate 
the  position  of  the  pay  which  may  not  be  too  close  to  the  bedrock. 

Level  Bedrock. — The  bedrock  should  be  near  enough  level  to  permit 
the  boats  to  float  over  all  the  ground  to  be  worked. 

Presence  of  Arsenic— The  presence  of  arsenic  or  anything  else  that 
will  prevent  free  amalgamation  makes  the  use  of  quicksilver  and 
riffles  of  little  avail,  and  cocoa  matting,  plush,  or  other  such  means 
must  be  adopted  to  save  the  gold,  especially  where  it  is  in  fi-ne 
particles. 

Drilling.— 1^ early  all  this  work  in  the  Sacramento  Valley  districts 
of  California  has  been  done  with  Keystone  drills.  No.  3  traction. 
Owing  to  the  presence  of  water  in  the  gravel  in  most  instances,  it 
has  been  found  impracticable  to  sink  shafts.  The  cost  of  the  drill, 
including  freight,  etc.,  is  about  $1,900  complete.  Three  men  are 
required  to  work  it,  w^ith  wages  from  $3.50  to  $4.00,  and  $2.50  and 
$2.00  per  day.  To  this  must  be  added  the  cost  of  fuel,  water,  repairs, 
etc.,  and  wages  of  one  or  two  men  to  do  the  sampling.  The  sampling, 
if  properly  done,  would  require  a  skilled  man,  and  his  pay  might  add 
much  to  the  cost.  The  total  cost  per  day  to  run  the  drill  and  do  the 
sampling  varies  from  $15  to  $30.  About  12  or  15  feet  per  day  is  a 
good  average  speed  for  sinking  in  the  gravels  of  the  Sacramento  River 
basin.  With  larger  bowlders  and  harder  ground  the  cost  might  be 
materially  increased. 


ILL.    No.   29.     KEYSTONE    DRILL    AT    WORK    AT    OROVILLE    TO    PROSPECT    FOR    THE 
VALUES,  AND  DETERMINE  CHARACTER  OF  THE  GRAVEL. 


GOLD  DREDGIXG  IX  CALIFORNIA.  63 

In  comparatively  shallow  ground,  where  there  is  not  much  water, 
it  is  much  more  economical  to  sink  shafts  than  to  drill,  and  the  results 
will  be  found  more  satisfactory. 

By  proper  sampling  is  meant  the  determination,  from  a  compara- 
tively small  sample,  of  the  values  in  a  much  larger  volume  of  the  same 
material.  Care,  judgment,  and  experience  are  necessary,  and  all  such 
work,  whether  done  by  drilling  or  by  sinking  shafts,  should  be  put 
in  charge  of  an  experienced  man.  Gravel  lifted  by  drills  or  taken  from 
a  shaft  must  ])e  accurately  measured  or  weighed,  and  proper  allowances 
made  for  expansion  when  loosened.  Allowance  must  be  made  for 
excess  of  bowlders  not  sampled,  and  for  excess  of  gravel  beyond  the 
normal  width  of  the  drills  that  may  come  in  and  be  lifted. 

Prospecting. — There  is  no  rule  as  to  the  number  of  holes  that  should 
be  sunk.  ]\Iore  drill  holes  would  be  required,  to  give  satisfactory 
results,  than  shafts.  If  the  values  are  comparatively  evenly  distrib- 
uted over  the  tract  to  be  examined,  fewer  holes  would  enable  nearer 
approach  to  a  correct  estimate  of  values  than  where  the  pay  is  uneven. 
In  districts  where  the  character  and  values  are  comparatively  well 
known  in  parts  of  the  gravel  that  have  been  sampled,  less  careful 
examination  i>s  necessary  on  intervening  tracts  in  order  to  determine 
most  of  the  conditions  and  even  the  values. 

Errors  in  Sampling  frequently  occur  from  the  squeezing  in  of 
material  around  the  bottom  of  the  casing,  so  that  more  gravel  than 
is  called  for  by  the  size  of  the  hole  is  lifted.  A  check  on  this  is  to 
drill  and  pump  in  a  section  of  a  foot  or  so  and  weigh  the  material. 
Sliming  and  consequent  loss  of  gold  sometimes  result  when  too  long 
a  period  of  churning  transpires  before  pumping  the  hole. 

The  casing  should  be  kept  driven  below  the  point  of  drilling,  when- 
ever possible. 

Fi)if  6'o?f/.— AVhen  the  gold  is  as  fine  as  at  Oroville  or  Folsom.  the 
pan  and  rocker  will  not  save  all  of  it,  but  will  save  all  that 
the  best  saving  tables  in  the  dredges  will  save,  and  may  save  consid- 
erably more.  But  when  it  is  considered  that  if  some  of  the  finest  gold 
now  being  saved  be  shaken  up  in  a  bottle  of  clear  water  it  will  take 
one  or  two  hours  to  settle,  there  can  be  no  question  that  some  is  lost 
whether  the  sampling  is  done  by  panning  or  rocking,  and  also  in  the 
sluicing.  How  much  this  is  could  be  determined  by  gathering 
samples,  especially  of  the  water  from  the  pans  and  rockers  and  also 
at  the  ends  of  the  sluices  and  subjecting  them  to  proper  tests.  It  would 
seem  that  this  work  should  be  undertaken  and  carefully  carried  out  by 
the  dredge  people.  If  much  gold  is  being  lost,  there  is  a  spur  to 
ino-enuitv  in  devising  means  for  saving  it. 


64 


GOLD    DREDGING    IN    CALIFORNI. 


JVl, 


JV'S. 


So//     0'-4^' 

f/ne  Grat^e/    -^  -e'^ 

Coarse  Grave/  ei- 


ySanc/  /6-eo' 
fineGrai/e/  20-2/' 

Coarse 
Gra\/'e/  <?/  '-^a ' 

'E§^^'^^(^^<^ye/  es-jr/ 

Coarse 
Grave/  3/-j9i' 

Bed  roc  A 


JV''2. 


C\se  Grcrve/ 
3-a- 

f/he  GrcTi'e/ 
'  /o' 


•Sane/  29-3/' 
Bec/roc/< 


Wcr/-er\ 
Le\/e/l 


/3'-22 


So//  o'-^' 
r/ne  Grave/ 
Sar/c/  e'-/o' 


Coarse 


F//^e  Grot^e/ 

37~-9-s' 

Coarse 
Gra^e/  ^s'-ss' 

/3eo/rocA 

ILL.  Xo.  30.     TYPICAL  VERTICAL  SECTIONS  OF  BORINGS  IN  FOUR  DIFFFRFNT  CALI 
FORNIA  FIELDS.  '      ' 


GOLD  DREDGING  IN  CALIFORNIA.  65 

The  following  tables  show  the  form  in  which  notes  of  the  sampling 
have  been  kept  in  making  an  examination  at  Folsom : 

Column  marked  "a"  indicates  colors  of  tine  and  tiour  gold,  smaller  than  "b"  size. 
Column  marked  "b"  indicates  colors  of  size  estimated  25  to  1  cent. 
Column  marked  "c"  indicates  colors  coarser  and  heavier  than  "b"  size. 


April   11,   1904— Hole  No.    1. 


Xo.  of 
Feet. 


No.  of  Colors. 


Surface  line. 
Sand  and  gravel. 


1  pan. 


4 
5 

6 

Loose  gravel. 

6 

6 

0 

Hole  ih  ft.  6  p.  M. 
April  12,  7:30,  started 

2  pans. 

8 
9 

Loose  gravel. 

30 

8 

2 

5  pans. 

10 
11 
12 

Loose  gravel. 

15 

4 

0 

Rockered. 

13 
14 

Bedrock. 

10 

0 

0 

No  water,  rockered. 

Total  

63 

18 

2  : 

i 

General  Remarks:  Drilled  14  feet  in  the  clay,  being  a  volcanic  ash  :  first  few  feet  a  light 
brown  color,  then  whitish,  down  as  far  as  we  drilled.     This  clay  is  called  "bedrock." 

Diameter  of  drill,  .5g  inches;  diameter  of  shoe,  7  inches;  casing,  .5f  inches,  inside 
diameter. 


66 


GOLD    DHKnfilXC;    IN    CALIFORNIA. 
April   15,   1904  -Hole  No.  4. 


No.  of 

M;iti'rinl. 

No 

.  of  Colors. 

Remarks. 

Feet. 

"a" 

"b" 

"c" 

0 
1 
2 
3 

Surface. 

Sand. 

Sandy  gravel. 

6 

1 

0 

4 

5 
6 

Sandy  gravel. 

10 

0 

0 

7 
8 
9 

Sandy  gravel. 

10 

1 

1 

10 
11 
12 

Gravel. 

5 

2 

0 

(Noon)  Water  line, 

12  ft. 

13 
14 
15 

Sand  and  gravel. 

15 

5 

1 

16 
17 
18 

Coarse  sand  and  gravel. 

10 

3 

0 

19 
20 
21 

Fine  mica. 

Sand. 

Gravel— yellow. 

10 

5 

1 

22 
23 
24 

Gravel— compact. 

15 

5 

2 

6  p.  M.  -Ajiril  IHth. 

25 
26 

27 

Gravel — compact. 

15 

4 

0 

28 
29 
30 

Gravel—compact. 

75 

120 

10 

31 
32 
33 

Gravel — compact. 
Bedrock. 

75 

120 

6 

Total 

246 

266 

21 

General  Remarks:    Cubic  feet  of  hole,  8.82.     Weight  of  gold,  2.85  grains;  value  of  gold. 
11.4  cents.     Value  per  cubic  yard,  34.85  cents. 


GOLD    DREDGING   IX    CALIFORNIA. 
April  22,   1904— Hole  No,  7. 


67 


Xo.  of 
Feet,  i 


Xo.  of  Colors. 


Surface. 
Fine  sand. 


'a"  showed  a  little  flour  gold. 


iiid  and  gravel.        i  8  1     '  0 


8  Sand  and  gravel. 

9 


Not  rockered  out. 
6  p.  M. 


11  Gravel. 

12 


13 
14 
15 

Gravel  and  sand.        i 

16 

1 

1 

Water  line,  14  feet. 

16 
17 

18 

Gravel  and  sand. 

■a{ 

1 

1 

19 
20 
21 

Gravel  and  sand. 

15 

4 

0 

22 
23 
24 

S 

! 
nail  gravel   and  gray 
sand— soft. 

25    1 

2 

1 

26  Sand  and  gravel. 

27 


.^  Compact  gravel. 

30  Cobbles. 


Of,      Coarse  sand  and  small 
33    i                  gravel. 

i 

15 

10 

3       6 

p.  M..  Sunday 

April  24th. 

34  Brown  gravel,  yellowish 

35  brown  water. 

36  Bedrock. 

10 

1 

0 

Total   

221 

29 

8 

General  Remarks:  Cubic  feet  of  hole,  9.62.  Weight  of  gold,  .95  grains ;  value  of  gold, 
3.8  cents.     Value  per  cubic  yard,  10  cents. 

Per  actual  measurement  we  took  out  of  hole  No.  7.  6.703  cubic  feet.  By  using  pipe 
factor  for  7-inch  hole  we  figure,  or  estimate,  9.62  citbic  feet,  making  a  difference  of  2.917 
cubic  feet  in  our  favor.  The  actual  dirt  taken  out  is  for  a  pipe  5J  inches  in  diameter 
and  7-inch  shoe. 


68 


GOLD  DREDGING  IN  CALIFORNIA. 


DREDGE-MINING  DISTRICTS  OF  CALIFORNIA. 


OROVILLE   DISTRICT. 

In  this  district  was  made  the  second  discovery  of  gold  in  California— 
abont  two  months  after  Marshall  made  his  discovery  at  Sutter's  mill 
in  January,  1848.     In  March,  General  John  Bidwell,  while  encamped 


ILL.  No.  ;il.     GENER.^L  VIEW  OF  THE  OROVILLE  DREDGING  DISTRICT. 

on  Feather  River,  at  Hamilton  Bend,  a  few  miles  beloAv  the  present 
town  of  Oroville,  on  his  way  to  his  ranch  from  Sutter's  Fort,  heard  of 
Marshall's  discovery.  He  decided  to  prospect,  and  soon  found  that 
gold  existed.  In  ^Nlay  of  that  year  the  first  camp  was  started  at  Morris 
ravine.  At  first  the  mining  was  done  above  Oroville  in  the  creeks  and 
on  bars  in  the  rivers  in  the  moimtains,  but  by  1856  there  were  many 
hundreds  of  white  men  working  in  the  present  dredging  field.  The 
richer  spots,  some  at  considerable  distance  from  the  river,  were  worked, 
but  the  places  of  these  white  men  were  soon  taken  by  Chinese,  who 
swarmed  over  the  fiat  ground.  It  is  estimated  that  by  the  later 
seventies  there  were  over  7,000  Chinese  working,  almost  entirely  with 


GOLD  DREDGING  IN  CALIFORNIA. 


69 


manual  labor,  in  these  grounds. 
Although  little  work  was  done 
below  the  water  level,  which 
was  always  a  number  of  feet 
above  bedrock,  large  sums  of 
gold  were  produced.  One  of 
the  present  dredge  companies 
says  that  in  working  over  some 
ground  that  had  previously 
been  exploited  by  the  whites  or 
Chinese  in  earlier  days,  they 
recovered  not  over  half  the 
values  recovered  from  adjoin- 
ing ground.  Much  of  the 
ground  in  this  district  was 
worked  by  whites  and  again  by 
the  Chinese,  and  now  is  being 
worked  for  the  third  time  with 
dredges. 

The  yardage  handled  by  the 
larger  dredges  with  ten  men  is 
as  much  as  Avould  require  500 
men  or  more  by  the  old 
methods. 

There  are  seventeen  com- 
panies in  the  Oroville  district, 
operating  28  dredges.  Of 
these,  27  are  of  the  continuous 
bucket  type,  and  one  of  the 
shovel  type.  The  total  amount 
of  holdings  of  these  companies 
is  5,343  acres.  In  addition, 
there  are  about  2,000  acres  held 
by  individuals  which  have  been 
proved  good  dredging  ground 
and  will  probably  be  mined. 
Besides  this,  there  is  considera- 
ble ground  of  lower  grade  that 
may  pay  to  dredge  as  the  costs 
of  working  shall  be  reduced, 
^lost  of  this  is  farther  down 
the  Feather  River  beyond  the 
present    fields,    but    of    similar 


70  GOI-n    DREDGING    IN    CALIFORNIA. 

material.  Tlie  total  cost  of  building  the  28  dredges  was  about  $1,550,- 
000.  In  addition,  machine  shops,  drills,  offices,  etc.,  would  make  the 
total  outlay  for  equipment  up  to  the  present  time  nearly  $2,000,000. 

Tlie  gold  yield  from  the  25  dredges  operating  in  this  district  in  1903 
was  $1,329,998,  according  to  the  United  States  Mint  reports. 

Prospecting. — Practically  all  the  prospecting  of  these  gravels  was 
done  with  drills,  there  being  too  much  water  in  the  ground  to  permit 
the  sinking  of  shafts. 

Values.  —  The  gold  is  comparatively  evenly  distributed  in  this  dis- 
trict, and  the  best  informed  make  a  minimum  estimate  of  the  average 
values  for  the  whole  7,500  acres  of  17  cents  per  cubic  yard.  Taking  the 
depth  of  the  gravel  at  10  yards,  this  would  make  the  probable  yield  a 
little  over  $60,000,000. 

Gravel. — The  depth  of  the  gravel  varies  from  26  to  42  feet,  and 
will  average  30  feet.  It  is  comparatively  loose,  a  clean  wash,  prac- 
tically free  from  clay,  and  contains  practically  no  bowlders  large 
enough  to  interfere  with  digging.  In  the  present  river  channel  and 
adjacent  ground  there  is  no  need  to  blast  the  banks,  but  in  some  of 
the  higher  ground  it  has  been  found  advisable  to  use  powder. 

Bedrock.  — The  false  bedrock  to  which  the  gravel  is  dredged  is  com- 
paratively flat  and  quite  soft,  being  merely  a  bed  of  volcanic  tuff 
carrying  other  gravels,  and  may  be  dredged  to  sufficient  depth  to  take 
up  all  that  bears  gold. 

Poi^er.  — Electric  power  is  usied  in  all  cases,  at  a  cost  of  1%  cents 
per  kilowatt  hour. 

Water.— An  excellent  ditch  system  supplies  water  in  all  parts  of 
the   district.     The   cost   averages   about  $125   per  month. 

Lahor.—Good,  experienced  labor  is  easily  obtained,  the  daily  wages 
being  usually,  for  foremen,  $5 ;  winchmen,  $3  and  $3.50 ;  other  laborers, 
generally  $2.50.  Some  Chinese  are  employed,  at  $1.75,  to  do  general 
work. 

Transporiation,  Supplies,  e^c— Rail  facilities  are  convenient,  the 
source  of  supplies  not  distant,  and  there  are  well-equipped  shops 
for  repairs. 

6^o/fZ.  — The  gold  is  comparatively  fine,  there  being  no  nuggets,  and 
20  per  cent  of  it  will  pass  through  a  150-mesh  screen.  HoAvever,  it 
easily  amalgamatas.     The  value  is  about  $18.50  per  ounce. 

Ideal  Conditions.  — Taking  all  things  into  consideration,  the  con- 
ditions are  almost  perfectly  ideal  for  successful  dredging. 

Area  Worked.  — There  has  been  dredged  since  March  1,  1886,  when 
the  first  dredo-e  began  work,  605  acres. 


GOLD    DREDGING    IN    CALIFORNIA. 


COMPANIES    OPERATING. 


Feather  Kiver  Exploration  Company,  John  J.  Hamlyn.  manager, 
Oroville.  In  Sees.  24  and  25,  T.  19  N.,  R.  3  E.  Area  of  holdings,  850 
acres.  This  company  installed  the  first  successful  dredge  ever  oper- 
ated in  California,  designed  by  R.  H.  Postlethwaite,  and  built  by  the 
Risdon  Iron  Works.  "Work  was  begun  ]March  1,  1898.  Prior  to  that, 
extensive  work  had  been  done  in  prospecting  and  examining  the  prop- 
erty. The  first  dredge  was  of  3  cu.  ft.  bucket  capacity,  and  the  com- 
pany has  since  constructed  four  5  cu.  ft.  bucket  dredges  of  the  Risdon 


ILL.  No.  .S3. 


DREDGE  or   THE  FE.\TIIi:K   R1\EK  EXPL0R.\TI0N  COMPANY,  OROVILLE. 
RISDOX  TYPE. 


type.  The  capacity  of  these  latter  is  40,000  cubic  yards  per  month, 
each  dredge  consuming  63  horse-power.  Revolving  screen  and  cocoa 
matting  and  expanded  metal  screens  are  used.  It  is  important  to  note 
that  this  company  makes  returns,  for  about  five  years'  work  with  these 
dredges,  of  a  cost  of  6  cents  per  cubic  yard.  In  this  connection  it 
should  be  considered  that  there  are  no  less  than  five  dredges  under  one 
management,  and  that  the  ground  in  which  they  are  working  is  not 
as  hard  as  is  some  of  the  Oroville  gravel.  The  extent  of  ground  worked 
is  150  acres.  The  companj"  contemplates  building  additional  dredges. 
(See  111.  No.  33.) 


ILL.  No.  34.     FRONT  END  OF  A  DIPPER  DPvEDGE. 


STACKER  END  OF  DREDGE,  SHOWING  HEIGHT  OF  TAILINGS  PILE.     LAVA 
BEDS  DREDGING  COMPANY,  OROVILLE. 


GOLD  DREDGING  IN  CALIFORNIA.  I  i 

Lara  Beds  Dredging  Cotnpany.  J.  W.  Goodwin,  president,  Sau  Fran- 
cisco. In  Sees.  19  and  30,  T.  19  X..  R.  3  E.  Area  of  holdinos,  700 
acres.  This  company  began  work  in  1900,  and  has  two  dredges  at 
work,  of  5  cu.  ft.  bucket  capacity,  Bncyrus  type.  The  extent  of  ground 
worked  is  25  acres.  The  company  returns  as  the  average  approximate 
cost  of  dredging.  8  cents  per  cubic  yard.     (See  111.  No.  35.) 

Oroville  Gold  Dredging  Company,  F.  S.  Mayhew,  .secretary,  San 
Francisco.  In  Sec.  25,  T.  19  N.,  R.  3  E.  Area  of  holdings,  66  acres. 
This  company  operates  one  dredge  of  the  ]\Iarion  steam  shovel  type, 
which  has  been  working  since  February,  1901,  and  which  has  dug 
since  then  20  acres  of  ground.  The  cost  of  the  plant  is  $45,000.  The 
digging  capacity  of  this  dredge  is  returned  by  the  ownei^  as  being 
from  18,000  to  24,000  cubic  yards  per  month.  It  is  valuable  to  note 
in  this  case  that  the  horse-powder  consumed  is  only  40.  The  owners 
make  no  returns  as  to  the  cost  of  dredging  per  cubic  yard,  but  claim 
very  satisfactory  results.     (See  111.  Xo.  36.) 

Centred  Gold  Dredging  Company,  F.  S.  Mayhew,  secretary  and 
manager,  San  Francisco.  In  T.  19  X.,  R.  4  E.  Area  of  holdings, 
150  acres.  Began  operations  in  ]\Iay,  1904.  This  company  operates 
one  Bucyrus  type  machine,  with  capacity  of  40,000  cubic  yards  per 
month.  The  bucket  capacity  is  3  cubic  feet.  The  gravel  is  30  feet 
in  depth.  The  details  of  the  machine  are  shown  in  table  of  dredge 
data  accompanying  this  bulletin. 

Indiana  Gold  Dredging  and  Mining  Company,  0.  C.  Perry,  man- 
ager, Oroville.  In  Sees.  13  and  18,  T.  19  X.,  R.  4  E.  Area  of  holdings, 
175  acres.  This  company  began  operations  July  1,  1901,  and  has 
two  dredges  at  work,  each  of  3  cu.  ft.  bucket  capacity,  of  the  Bucyrus 
type,  built  at  a  cost  of  $50,000  each.  The  horse-power  consumed  on 
these  dredges  is  100.  The  actual  average  digging  capacity  of  these 
dredges  is  returned  at  42,000  cubic  yards  per  month.  Forty  acres 
of  ground  has  been  worked.  The  owners  return  the  cost  of  working 
at  71  o  cents  per  cubic  yard.     (See  111.  Xos.  37  and  38.) 

Kia  Ora  Golel  Dreelging  Company,  R.  H.  Postlethwaite,  president. 
San  Francisco.  In  Sec.  3,  T.  19  X.,  R.  3  E.  Area  of  holdings,  153 
acres.  This  company  began  work  in  ]\Iay,  1899,  and  has  dredged  40 
acres  with  one  dredge,  of  3i/o  cu.  ft.  bucket  capacity,  of  the  Risdon 
type.  The  gravel  is  of  an  average  depth  of  28  feet,  which  is  consid- 
erably less  than  the  average  of  the  district.  This  company  returns  as 
the  cost  of  working  4  cents  per  cubic  yard,  and  gives  the  capacity  of 
the  dredge  at  31.800  cubic  yards  per  month.     (See  111.  Xo.  39.) 


78  (JOLD    DREDGINO    IN    CALIFORNIA. 

Cherokee  Gold  Dredging  Company,  L.  J.  Hohl,  manager,  Orovilk-. 
Jn  Sec.  3,  T.  18  N.,  R.  ,3  E.  Area  of  holdings,  200  acres.  This 
company  began  operations  in  October,  1902,  with  a  Bncynis  dredge 
of  5  en.  ft.  bncket  capacity,  and  has  worked  16  acres  of  ground.  The 
cost  of  equipment,  including  a  machine  shop  and  a  pumping  station, 
was  $80,000.  The  company  contemplates  building  another  dredge. 
The  horse-power  consumed  on  the  dredge  is  120,  and  the  compan>- 
makes  return  of  cost  of  working  at  7  cents  per  cubic  yard.  (See  III. 
No.  40.) 

Pemisylvania  Dredging  Company,  Sam  W.  Cheyney,  manager,  San 
Francisco.  In  Sec.  25,  T.  19  N.,  R.  3  E.  Area  of  holdings,  152  acres. 
This  company  began  operations  in  October,  1902,  and  has  worked  25 
acres.  Its  dredge  was  built  by  the  Golden  State  and  Miners'  Iron 
Works  of  San  Francisco,  with  buckets  of  5  cu.  ft.  capacity.  The  aver- 
age horse-power  consumed  is  140.  The  cost  of  the  dredge  was  $70,000. 
The  average  number  of  cubic  yards  dug  per  month  during  the  year 
1903  was  43,830.  The  cost  of  dredging  is  returned  at  8I/2  cents  per 
cubic  yard.  This  dredge  has  a  different  system  of  screening  from 
the  others  in  the  district,  in  that  there  are  two  screens  used,  one  above 
the  other,  of  the  shaking  screen  type.  In  the  upper  screen  the  holes 
are  l^^  inches  in  diameter,  and  in  the  lower  screen  14  iii^h  in 
diameter.     (See  111.  Nos.  41  and  42.) 

Butte  Gold  Dredging  Company,  B.  Noyes.  secretary,  San  Francisco. 
In  Sec.  7,  T.  19  N.,  R.  4  E.  Area  of  holdings,  85  acres.  This  com- 
pany began  operations  November  26,  1902,  and  has  worked  15  acres 
with  one  Bucyrus  dredge,  of  31/0  cu.  ft.  bucket  capacity.  The  cost  of 
the  dredge  was  $50,000.  The  horse-power  consumed  is  about  80.  The 
actual  average  digging  capacity  of  the  dredge  for  the  first  thirteen 
months  of  its  operation  was  47,640  cubic  yards  per  month.  The  owners 
return  the  average  cost  of  the  digging  and  all  other  expenses  at  7  cents 
per  cubic  yard. 

American  Gold  Dredging  Company,  F.  S.  i\Iayhew,  secretary,  San 
Francisco.  Area  of  holdings,  275  acres.  The  company  began  opera- 
tions in  November,  1902,  with  a  3  cu.  ft.  Bucyrus  dredge,  and  has  since 
built  a  5  cu.  ft.  bucket  dredge  of  the  same  type.  The  digging  capacity 
of  the  3  cu.  ft.  dredge  is  returned  at  45  cubic  yards  per  minute.  The 
return  of  the  actual  average  dug  by  the  5  cu.  ft.  bucket  is  90,000 
cubic  yards  per  month  for  the  first  six  months,  and  the  cost  of  digging 
during  that  period,  including  all  expenses,  such  as  office,  management, 
etc.,  is  placed  at  3  cents  per  cubic  yard.  These  figures  are,  of  course, 
unusual  both  as  to  the  yardage  and  as  to  the  cost  per  cubic  yard.    The 


±:-^Ta 


80 


GOLD  DREDGING  IN  CALIFORNIA. 


company  was  reluctant  to  give  out  these  figures  unless  it  would  be 
stated  that  during  the  six  months'  running  there  were  no  breakdowns, 
and  consequently  no  cost  for  repairs;  also,  that  there  was  so  little  loss 
of  time  that  this  large  yardage  was  made  possible.  The  cost  of  the 
5  eu.  ft.  dredge  was  $70,000,  and  the  average  of  the  horse-power  con- 
sumed, 100. 

El  Oro  Dredging  Company,  B.  Noyes,  secretary,  San  Francisco.  In 
Sees.  17  and  20,  T.  19  N.,  R.  4  E.  Area  of  holdings,  220  acres.'  This 
company  began  operations  in  December,  1903,  and  has  worked  five 
acres.       Its  dredge  was  built  by  the  Link  Belt  Machinery  Company,  of 


ILL.  No.  41.     PENNSYLVANIA  GOLD  DREDGING  COMPANY. 

Chicago,  with  buckets  of  5  cu.  ft.  capacity,  close  connected.  They 
claim  an  average  capacity  of  75,000  cubic  yards  per  month.  In  respect 
to  screens,  sluicing  table,  and  stacker,  it  is  similar  to  the  Bucyrus  type. 
The  company  proposes  to  build  another  dredge.     (See  111.  No.  43.) 


James  H.  Leggeti,  Oroville.  In  Sec.  18,  T.  19  N.,  R.  4  E.  Area  of 
holdings,  70  acres.  Mr.  Leggett  began  operation's  March  31.  1904,  with 
a  Risdon  dredge  of  5  cu.  ft.  bucket  capacity.  He  returns  the  average 
digging  capacity  as  45,000  cubic  yards  per  month.  The  horse-power  is 
placed  at  100,  and  the  approximate  average  cost  of  dredging  per  cubic 
yard  at  5  cents.    Five  acres  have  been  worked.     (See  111.  No.  10.) 


82 


GOI.D    DREDGIXG    IX    CALIFORNIA. 


Vilofo  Syiulicate,  JJinittd,  J.  W.  Pew,  secretary,  San  Francisco. 
In  Sees.  19  and  30,  T.  19  N.,  R.  4  E.  Area  of  holdings,  200  acres. 
This  company  began  operations  November  1,  1904,  with  one  dredge  of 
the  Bncyrus  type,  5  cu.  ft.  bucket  capacity.  As  they  have  only  lately 
begun  work,  no  returns  as  to  capacity  are  available.     (Seie  111.  No.  44.) 

Ovoville  Gold  Dredging  and  Exploration  Company,  C.  11.  Munro, 
manager,  Oroville.  In  Sees.  24  and  25,  T.  19  N.,  R.  4  E.  Area  of  hold- 
ings, 600  acres.  This  company  began  operations  in  April,  1902,  with 
a  Risdon  dredge  of  4  cu.  ft.  bucket  capacity,  and  in  1905  also  started 


ILL.  No.  43.  EL  ORO  DREDGING  COMPANY'S  DREDGE,  OROVILLE.  LINK  DREDGE 
MACHINE  COMPANY'S  TYPE. 

working  a  new  Bueyrus  dredge  (Biggs  No.  2)  with  5  cu.  ft.  buckets. 
This  latter  dredge  has  a  record  of  109,630  cubic  yards  dug  for  thirty 
days  from  April  1st  to  April  30th  inclusive.  Details  of  the  work  and 
its  cost  are  given  elsewhere  in  this  Bulletin,  as  are  details  of  sizes,  etc., 
of  both  dredges.  The  very  full  tables  of  costs  of  operations  were  pre- 
pared by  Mr.  Munro.     (See  111.  No.  11.) 

Boston  and  Oroville  Mining  Company,  William  P.  Hammon,  man- 
ager, Oroville.  In  Sees.  13,  23,  and  24,  T.  19  N.,  R.  3  E.,  and  Sees. 
17  and  18,  T.  19  N.,  R.  4  E.  Area  of  holdings,  650  acres.  This  com- 
pany began  operations  in  July,  1901,  and  has  worked  100  acres  of 


GOKD  DREDGING  IX  CALIFORNIA. 


83 


ground.  Three  dredges  are  operating',  two  of  the  Risdon  and  one  of  the 
Bueyrus  type,  each  of  5  cii.  ft.  bucket  capacity.  The  cost  of  equip- 
ment was  $175,000.  Revolving  screens  are  used  in  the  Risdon  dredges, 
and  shaking  screens  in  the  Bueyrus.  However,  in  all  these  dredges 
Hungarian  riflfles  and  quicksilver  are  used  in  preference  to  cocoa  mat- 
ting and  expanded  metal.  It  will  be  seen  that  this  is  also  true  of  the 
dredges  owned  by  the  Boston  and  California  Dredging  Company  and 
indicates  the  preference  in  the  district  for  riffles  and  quicksilver  over 
the  cocoa  matting,  and  a  belief  that  where  there  is  no  arsenic  or  other 
material  to  prevent  the  free  amalgamation,  the  riffles  and  cpiicksilver 


ILL.  Xu.  U.    VILORO  DREDGE.  OROVILLE  FIELD.     LATEST  TYPE  OF  BUCYRUS  DREDGE. 

will  save  more  of  the  fine  gold  than  will  the  matting.     The  company 
proposes  to  build  additional  dredges.     (See  111.  Xos.  45  and  46.) 

Boston  and  California  Dredging  Company.  AVilliam  P.  Hammon. 
manager,  Oroville.  In  Sees.  18  and  19,  T.  19  X..  R.  4  E.  Area  of 
holdings,  300  acres.  Operations  were  commenced  in  Alarch.  1902,  and 
about  60  acres  of  ground  have  been  worked.  The  company  is  operating 
three  dredges,  all  of  different  types— one  being  a  Risdon,  with  open-con- 
nected buckets  and  a  bucket  conveyor :  one  a  BucyriLS  dredge,  with  close- 
connected  buckets  and  belt  conveyor,  and  the  third  a  Clarion  Steam 
Shovel   Company   dredge,   with   continuous   chain    buckets,    similar  to 


86 


)M)    DHKIXilXti    IX    CALIFORNIA. 


those  Oil  the  others,  close  eonueeted.  'J'he  iiuuiageiueiit's  returns  of  the 
digging:  capacity  of  these  dredges  are:  for  the  Eisdon,  45,000  cubic 
yards;  for  the  Bucj-riis,  60,000  cubic  yards;  and  for  the  Marion, 
90,000  cubic  yards  per  month.  It  may  be  stated  here  that  if  it  were 
not  that  the  dredges  were  built  in  the  order  named,  so  that  the  last  built 
had  advantages  over  the  others  in  stronger  construction,  there  would 
not  be  so  much  difference  in  the  yardage  handled.  Then,  again,  it 
may  be  said  in  favor  of  the  Risdon  dredge  that  the  horse-power  is  less. 
However,  it  may  be  said  in  regard  to  the  IMarion  that  the  company 
claims  that  the  construction  of  the  screen  enables  the  washing  of  larger 


ILL.  No.  47.     "CALIFORNIA   No.  3,"  BOSTON   AND   CALIFORNIA   DREDGING    COMPANY 
OROVILLE.     BUILT  BY  MARION  STEAM  SHOVEL  COMPANY. 


quantities  of  gravel  than  do  the  other  screens,  and  in  this  way  permits 
a  larger  amount  of  gravel  to  be  handled.  A  number  of  the  managers 
at  Oroville  have  stated  that  the  sluicing  capacity  or  the  gold-saving- 
capacity  of  the  dredges  was  not  sufficient  to  handle  all  the  gravel  that 
might  possibly  be  raised.  The  screen  on  the  Clarion  dredge  is  of  the 
revolving  type,  somewhat  conical  in  shape,  growing  smaller  with 
offsets  toward  its  outlet.  These  offsets,  together  with  crossbars,  retard 
the  progi'ess  of  the  gravel  sufficiently  to  insure  perfect  washing.  How- 
ever, the  washing  capacity,  it  is  claimed,  was  increased  fifty  per  cent. 
(See  111.  No.  47.) 


ILL.  X...  4',».     FROXT  VIEW  OF  MARIiioLD  CoMPANVS   DKKI>i>l".  AT  uROVILL 


88  GOLD  DREDGING  IN  CALIFORNIA. 

Marigold  Dredging  Company,  J.  W.  Goodwin,  president,  San 
Francisco.  In  Sees.  30  and  31,  T.  19  N.,  R.  4  E.,  and  Sees.  25  and  36, 
T.  19  N.,  R.  3  E.  Area  of  holdings,  467  acres.  Operations  were 
commenced  on  this  property  in  Jannaiy,  1900,  with  a  3  cu.  ft.  bucket 
Risdon  dredge.  Tliis  company  is  now  operating  one  5  cu.  ft.  Risdon 
dredge.  The  extent  of  ground  worked  is  50  acres.  (See  111.  Nos.  48, 
49  and  50.) 

.  Feather  Valley  Gold  Dredging  Company,  C.  Jackson,  manager,  San 
Francisco.  In  Sees.  4  and  5,  T.  18  N.,  R.  3  E.  Area  of  holdings, 
220  acres.     This  gi'ound  was  lately  purchased  and  was  drilled. 


YUBA  DISTRICT. 

In  this  district  no  dredging  was  done  until  August,  1904.  The  two 
dredges  built  by  the  Yuba  Consolidated  Gold  Fields  Company  are 
doing  contract  work  for  the  Government  retaining  dams.  They  are 
thus  making  their  tailings  of  value.  There  is  only  one  company 
actually  operating,  but  other  lands  have  been  drilled  and  it  is  estimated 
that  there  are  5,000  acres  of  gravel  suitable  for  dredging 

Prospecting.— This  w^as  done  with  drills. 

Values. — The  gold  is  comparatively  evenly  distributed  over  the 
district.  Estimates  place  the  values  at  from  15  to  35  cents  per  cubic 
yard.  As  the  gravel  is  much  deeper  than  that  in  the  Oroville  district, 
a  very  rough  estimate,  without  much  data  to  go  on,  of  the  probable 
total  yield  of  this  district  would  be  $50,000,000. 

Gravel.— The  depth  of  the  gravel  in  this  district  is  greater  than 
in  any  other  in  California,  the  Yuba  Consolidated  Gold  Fields  Com- 
pany digging  to  a  depth  of  60  feet.  It  is  a  loose,  clean  wash,  free  from 
clay,  and  contains  no  large  bowlders.  The  dredges  in  operation  use 
close-connected  buckets. 

Bedrock.-The  false  bedrock  to  which  the  gravel  is  dredged  is 
comparatively  flat  and  very  soft— a  volcanic  ash,  wdth  sand  doubtless 
overlying  other  gravels. 

Poifer.  — Electric  power  is  used. 

Lahor.—The  wages  paid  on  the  dredges  are  $4  for  winchmen  and 
$3  for  laborers.  Higher  wages  are  paid  than  at  Oroville,  in  order  to 
obtain  more  efficient  men  for  larger  and  more  expensive  clredges. 

Transportation,  Sapplies.  efc— Rail  facilities  to  ]\Iarysvil]e  are 
srood,  and  a  better  wagon  road  is  being  built  to  the  tract. 


,J2 

;,^ 

t-M:^ 

^        !! 

yC^r- 

•;TArKP:R  KXrrOF  MARIGOLD  COMPANY'S  DRKDGK  AT  OROVILLE. 


ILL.  No.  51.     YUBA  COXSOLIDATED  GOLD  FIELDS'  DREDGES.  EACH  OF  0  CU.  FT.  BUCKET 
CAPACITY.     BUCYRUS  TYPE. 


GOLD  DKEDGIXG  IX  CALIFORNIA.  91 

6'o/(/.  — Tlie  gold  is  very  fine.  As  much  as  20  per  cent  will  pass 
through  a  150-mesh  screen.  It  readily  amalgamates,  the  dredge  nsing 
riffles  and  quicksilver.     The  value  is  about  $18.50  per  ounce. 

Ideal  Co;((?(7/o»s.— Practically  all  the  conditions  are  ideal  for  suc- 
cessful  and  economical  dredging. 

Yiiha  Consolidated  Gold  Fields,  Newton  Cleveland,  manager, 
]Marysville.  In  T.  16  X.,  K.  5  E.,  ten  miles  east  of  Marysville,  on  the 
Yuba  River.  Area  of  holdings,  3,000  acres.  This  company  began 
operations  in  August,  1904,  and  has  a  contract  from  the  Federal  Gov- 
ernment for  building  a  retaining  dam  at  that  point.  Two  dredges  of 
the  Bucyrus  t^^e  of  6  cu.  ft.  bucket  capacity  are  now  at  work.  The 
company  has  contracted  for  four  more  dredges,  and  a  number  of 
others  are  contemplated.  The  cost  of  the  tAvo  dredges  now  in  opera- 
tion was  about  $200,000.  Shaking  screens,  Hungarian  riffles  with 
quicksilver,  and  belt  conveyors  are  used. 

It  is  notable  that  in  this  district  these  dredges  are  digging  to  a  depth 
of  60  feet,  which  is  more  than  50  per  cent  greater  than  the  depth  of  the 
gravel  in  the  other  Sacramento  Valley  districts.  These  dredges,  which 
are  new,  are  lifting  90,000  cubic  yards  per  month  each,  with  200  horse- 
power.      (See  111.  Xos.  51  and  52.) 


BEAR  RIVER  DISTRICT. 

.Irta.— About  1.000  acres  of  gravel  on  the  Bear  River  near  Wheat- 
land have  been  drilled  systematically  and  proved  of  sufficient  value  to 
dredge. 

Gravel.  — The  dei)th  of  the  gravel  averages  about  30  feet.  It  is  all 
a  clean  wash,  free  from  clay  and  with  no  large  bowlders. 

Bedrock. —  This  is  volcanic  ash.  similar  to  that  at  Folsom  and 
Oroville. 

Poiver.— There  is  electric  power  available,  at  a  cost  similar  to  that 
at  Oroville,  namely,  l^/o  cents  per  kilowatt  hour. 

Wages.— Yor  winchmen  and  laborers,  this  will  be  about  $3.50  and 
$2.50  per  day  respectively. 

Transportation,  Supplies,  etc.  — There  are  convenient  rail  facilities 
with  San  Francisco,  and  the  neighboring  farming  country  is  a  source 
of  supplies. 

Gold.  — The  gold  is  comparatively  very  fine,  twenty  per  cent  of  it 
impalpable,  and  in  value  about  $18.50  per  ounce. 


92  GOI.D    DREDGING    IX    CALIFORNIA. 

Conditions.  — All  the  conditions  are  as  favorable  as  those  at  Oroville, 
and  very  similar. 

Bear  River  3Iining  Company,  subsequently  called  Bear  River 
Exploration  Company,  R.  D.  Evans,  Boston,  Location,  near  Wheat- 
land. Area  of  holdings,  1,000  acres.  There  are  four  Risdon  dredges, 
two  of  which  began  operations  in  July,  1900,  and  the  other  two  began 
in  1902.  The  first  two  have  3i/4  cu.  ft.  buckets,  and  the  last  two  4 
cu.  ft.  buckets.  The  latter  have  a  capacity  of  50,000  cubic  yards  per 
month.  The  gravel  runs  from  40  to  50  feet  in  depth,  and  has  some 
clay  with  it.  Details  of  dredges  are  given  in  the  large  table  accom- 
panying this  Bulletin. 

FOLSOM  DISTRICT. 

There  are  in  this  district  five  companies  operating  eight  dredges, 
none  of  which  use  less  than  5  cu.  ft.  buckets.  The  largest  dredge 
has  buckets  of  13  cu.  ft.  capacity.  Starting  later  than  the  operators 
at  Oroville,  they  have  made  use  of  w^hat  has  been  learned  there,  and 
discarded  all  small  dredges.  The  work  is  in  the  hands  of  people  with 
plenty  of  capital  and  skilled  engineers.  One  of  the  companies  has  a 
machinery  plant  larger  than  any  other  in  California,  outside  of  San 
Francisco,  and  is  prepared  not  only  to  do  its  own  repairing,  but  also 
to  build  its  own  dredges.  This,  of  course,  means  a  large  saving  of 
cost  in  repairing,  and  it  indicates  how  companies  with  large  areas  to 
be  worked  and  many  dredges  employed  may  very  largely  reduce  the 
cost  of  dredging. 

Area.  — The  Folsom  district,  as  it  is  called,  extends  from  the  town  of 
Folsom  to  a  short  distance  below  the  Fair  Oaks  bridge  along  the 
American  River,  a  branch  of  the  Sacramento,  and  in  Sacramento 
County  a  distance  of  six  miles,  or  a  little  more.  Most  of  the  gravel 
is  on  the  south  side  of  the  river,  and  is  in  width,  generally,  from  1  to 
114  miles.  The  area  of  the  gravel  that  has  so  far  been  acquired  by  the 
company,  after  investigation,  is  about  5,000  acres. 

Prospecting.— VYSiCtlcullY  all  the  prospecting  of  these  gravels  has 
been  done  with  drills,  there  being  too  much  water  in  the  ground  to 
permit  the  sinking  of  shafts. 

Values.— Tl\Q  gold  is  comparatively  evenly  distributed  over  the  dis- 
trict, and  the  results  of  the  drill  samples  indicate  that  the  gravel  will 
average  from  15  to  25  cents  per  cubic  yard.  Taking  the  depth  of  the 
gravel  as  10  yards,  this  would  make  the  probable  yield  over  $40,000,000. 

Gravel.— "Yho.  depth  of  the  gravel  is  from  16  to  50  feet,  and  in  this 
respect  varies  more  than  does  that  at  Oroville,  because  it  is  not  spread 


GOLD  DREDGING  IX  CALIFORNIA.  93 

over  as  wide  an  area.  The  average  is  about  30  feet.  The  gravel  is  all 
a  very  clean  wash.  In  this  connection  it  may  be  said  that  shaking 
screens  are  used  instead  of  revolving  screens  in  all  except  one  dredge. 
There  are  no  large  bowlders  to  interfere  with  digging,  and  it  may  also 
be  said  that  with  the  exception  of  the  one  dredge,  all  the  buckets  are 
close-connected.  Except  on  some  of  the  higher  benches,  where  there 
is  cement,  there  has  been  no  need  to  use  powder  for  blasting. 

Bedrock.— The  bedrock  here,  as  at  Oroville,  is  a  volcanic  ash,  or  false 
bedrock,  which  may  be  dug  without  difficulty,  and  under  which  there 
is  probably  other  gravel  overlying  the  real  bedrock. 

Poiuer.  — Electric  power  is  used  in  all  cases,  at  a  cost  of  0.65  of  a 
cent  per  kilowatt  hour.  This  is  against  II/2  cents  per  kilowatt  hour 
paid  at  Oroville,  or  less  than  one-half— an  important  consideration  in 
the  working  costs. 

Water. — There  is  an  abundance  of  water,  supplied  at  low  rates. 

Labor. — Experienced  labor  is  easily  obtained,  the  wages  being 
usually  $5  for  foremen,  and  $3  and  $3.50  for  winchmen.  Other  laborers 
are  paid  from  $2  to  $2.50. 

Transportation,  Supplies,  etc. — There  is  a  railroad  into  the  district. 
The  source  of  supplies  is  San  Francisco  and  Sacramento,  with  low 
rates  of  freight. 

Gold. — The  gold  is  comparatively  very  fine  in  size  of  particles,  and 
the  size  of  holes  in  the  screens  is  usually  three-eighths  of  an  inch,  as  at 
Oroville.    The  mint  value  of  the  gold  is  about  $19  per  ounce. 

Conditions.  —  Taking  all  things  into  consideration,  the  conditions  are 
ideal  for  economic  working. 

Agriculture. — Not  over  one-half  of  the  5,000  acres  of  dredging 
ground  in  the  Folsom  district  is  of  any  value  for  agriculture.  The 
value  of  the  rest  of  the  ground  could  not  be  placed  at  more  than  $100 
per  acre,  or  a  total  of  $250,000  for  the  whole  tract.  The  yield  in  gold 
from  this  district  will  exceed  $40,000,000,  according  to  the  estimates  of 
values  made.  The  value  of  this  gold  to  the  State  at  three  per  cent  per 
annum  would  amount  to  more  than  four  times  as  much  each  year  as  the 
total  value  of  the  ground  for  agriculture.  Then,  of  course,  it  may  in 
time  be  reclaimed  for  agriculture,  as  lands  of  that  character  become 
more  valuable. 

Debris. So  far  there  has  been  no  dredging  in  the  river  and  no 
debris  whatever  has  been  sent  down  by  these  dredges.  In  time,  the 
river  bed  may  be  dredged,  but,  as  at  Oroville,  this  can  be  done  without 
detriment. 


GOLD    DREDGING    IX    CALIP^ORNIA. 


95 


companip:s  operating. 

The  AshhuHoii  Mlniiifj  ('oiiip<(iiy,  Robert  E.  Cranstou,  mauager. 
Sacramento.  In  Sees.  5.  6,  7,  and  8,  T.  9  X.,  R.  7  E.,  American  River 
District,  Sacramento  Connty.  Area  of  holdings,  310  acres.  This 
company  began  operations  ^Nlarch  1,  1899,  Avith  a  dredge  that  was 
bnrned  May  25,  1903.  Its  new  dredge,  made  by  the  company  at  a  cost 
of  $120,000,  of  the  Bncyriis  tjTDC,  has  not  been  long  in  operation,  but 
the  cost  per  cnbic  yard  for  Avorking  is  estimated  at  more  than  5  cents. 
Another  dredge  Avill  be  Ijiiilt.  The  area  of  ground  worked  is  20  acres. 
(See  111.  No.  53.) 


ILL.  No.  :>i.     "EL  DORADO  No.  1,"  FOLSOM  FIELD.     LATEST  TYPE  OF  RISDON  BOAT. 
[Began  operations  May  1, 1905.] 

El  Dorado  Gold  Dredging  Company,  E.  H.  Benjamin,  secretary, 
San  Francisco.  In  T.  9  X.,  R.  6  E.,  and  T.  9  X.,  R.  7  E.,  American 
River  District,  Sacramento  Connty.  Area  of  holdings,  550  acres. 
This  company  has  prospected  its  ground  with  drills  and  is  now  operat- 
ing a  Risdon  7  cu.  ft.  bucket  dredge.  Began  operations  April  25,  1905. 
(See  111.  Xo.  54.) 

Colorado-Pacific  Gold  Dredging  Company,  O.  B.  Perry,  manager. 
In  T.  9  N.,  R.  7  E.  Area  of  holdings,  200  acres.  Has  two  dredges, 
the  first  of  which  began  work  in  April,  1899,  and  the  other  in  1902. 
Both  are.  of  the  Risdon  type ;  one  with  buckets  of  3i/4  cu.  ft.  capacity, 


98  GOLD  DREDGING  IN  CALIFORNIA. 

and  the  other  5  en.  ft.  The  smaller  machine  has  a  capacity  of  35,000 
i'ul)i('  yards  per  month;  the  larf^e  one  averages  60,000  cubic  yards  per 
month.  This  company  is  working  in  hard  ground,  for  which  reason 
one  dredge  is  being  rebuilt.     (See  111.  No.  55.) 

Folsom  Development  Company  and  Syndicate  Mining  Company. 
(Both  companies  under  one  management.)  [All  information,  even 
in  such  simple  matters  as  capital  stock  of  corporations,  acreage  of  hold- 
ings, etc.,  refused  by  the  manager— the  only  instance  of  the  kind  in 
the  State.    Lewis  E.  Aubury,  State  Mineralogist.]      (See  111.  No.  56.) 

CALAVERAS  COUNTY. 

So  far  there  is  being  exploited  and  considered  in  this  county  one 
small  tract  of  ground,  which  is  described  in  the  folloAving  paragraph, 
and  at  prasent  no  other  lands  in  the  county  ai-e  being  considered  with 
a  view  to  dredging. 

Calaveras  Gold  Dredging  Company,  C.  M.  Derby,  manager,  Jenny 
Lind.  In  T.  3  N.,  R.  10  E.,  M.  D.  M.,  on  the  Calaveras  River.  Area 
of  holdings,  350  acres.  This  company  began  operations  in  February, 
1904,  with  a  Bucyrus  dredge  of  5  cu.  ft.  bucket  capacity.  Electric 
power  is  used.  The  cost  of  the  plant  is  $75,000.  Wages  are  $3  for 
winchmen,  and  $2.50  for  laborers.  The  average  depth  of  the  gravel  is 
35  feet,  and  it  is  a  clean  gravel  wash,  free  from  clay,  with  a  few  large 
bowlders.  The  bedrock  is  a  volcanic  ash  similar  to  that  at  Folsom  and 
Oroville.    About  8  acres  of  ground  has  been  worked. 

PLUMAS  COUNTY. 

In  Plumas  County,  so  far  as  prospecting  has  developed,  about  1,500 
acres  of  dredging  ground  has  been  proved. 

SHASTA  COUNTY. 

There  are  two  dredges  at  work  in  Shasta  County,  both  near  Redding, 
and  described  in  following  paragraphs.  The  holdings  of  these  two 
companies  amount  to  1,096  acres.  Along  Cottonwood  Creek  and  its 
tributaries  are  large  areas  which  are  being  considered,  amounting 
to  3,000  or  4,000  acres.  Some  drilling  has  been  done,  but  very  little 
of  this  area  has  been  proved  of  value.  The  gravel  in  the  Cottonwood 
country  and  the  bedrock  are  similar  to  that  at  Oroville,  although  the 
gravel  Ls  generally  shallower.  On  Clear  Creek  an  additional  2,000 
acres  is  being  considered.     (See  111.  No.  57.) 

No  estimates  of  values  were  given  by  the  Shasta  owners  except  by 
the  Detroit  and  California  Mining  Company,  who  report  a  recovery 
of  from  25  cents  to  $1.50  per  cubic  yard  in  Clear  Creek. 


GOLD  DREDGING  IX  CALIFORNIA. 


99 


As  to  power,  it  may  be  said  that  the  Huron  Submarine  Alining  and 
Construction  Company  uses  steam,  with  crude  oil  for  fuel,  at  a  cost 
of  $3  per  horse-power  per  month,  while  the  Detroit  and  California 
Mining  Company  uses  electric  power  at  a  cost  of  $5  per  horse-power 
per  month. 

Huron  Siihmarine  Mining  and  Construction  Company,  G.  A.  DuBois, 
manager,  Redding.  In  Sec.  25,  T.  32  N.,  R.  5  W.  Area  of  holdings, 
396  acres.  This  company  began  operations  in  the  Sacramento  River, 
three  miles  above  Redding,  and  opposite  the  mouth  of  Middle  Creek. 


ILL.    No.   57 


THE    B?:DR0(K    of    the    SACRAMENTO    RIVER   AT  MOUTH   OF   MIDDLE 
CREEK,  ABOVE  REDDING. 


The  average  depth  of  the  gravel  is  from  8  to  25  feet.  It  is  blue  gravel 
with  many  bowlders.  The  gold  is  coarse  and  well  worn,  and  worth 
about  $19  per  ounce.  The  bedrock  is  of  igneous  series,  very  rough. 
The  dredge  is  unique,  having  neither  buckets  nor  shovels.  It  was 
built  by  the  company  on  its  own  plans.  The  boat  is  65  feet  long,  24 
feet  wide,  and  draws  2  feet  of  water.  A  75-horsepower  engine  operates 
a  rock  pump,  air  compressor,  and  auxiliary  machinery.  Oil  is  used 
for  fuel  at  $1.17  per  barrel,  making  the  cost  of  power  about  $3  per 
horse-power  per  month.  At  the  center  of  the  boat  is  a  steel  shaft  made 
with  sections  for  extending  to  any  required  depth.  Each  section  is 
boat-shaped.  8  feet  wide,  6  feet  high,  and  lli/o  feet  long.     (See  Illustra- 


100  GOLD  DREDGING  IN  CALIFORNIA. 

tions  Xos.  58  and  59.)  The  sharp  end  of  these  sections  heads  up  stream, 
ihns  ciittino'  the  water.  The  lower  sections  are  cylindrical,  the  lowest 
being  provided  with  a  water-tight  door  for  ingress  and  egress  of  divers. 
This  shaft  is  sunk  through  water  and  gravel  to  bedrock  gravel,  25 
leet  deep  being  worked  in  November,  1904.  Down  the  shaft  extends 
the  10-inch  column  of  the  rock  pump,  and  a  2-inch  rubber  hose  to  convey 
water  under  100  pounds  pressure  to  the  mouth  of  the  pump  column.  A 
diver  in  the  shaft  with  the  hose  in  hand  works  with  freedom,  direct- 
ing gravel  to  the  mouth  of  the  pump,  and  with  the  pressure  cleaning  the 
gold  from  crevices.  The  capacity  of  the  pump  is  1,500  cubic  yards  per 
day,  and  sufficient  water  to  wash' the  gravel  in  the  sluices.  The  divers 
receive  $125  per  month,  working  five  hours  each  day,  and  can  remain 
under  water  that  length  of  time  without  coming  to  the  surface.  The 
cost  of  the  plant  was  $110,000.  Four  men  are  required  for  a  crew. 
The  company  estimates  the  cost  of  dredging  at  3  cents  per  cubic  yard. 
They  express  an  intention  of  building  another  dredge  of  a  larger  size. 

Detroit  and  California  Mining  Company,  T.  R.  Heintz,  president 
and  manager,  Redding.  In  Sec.  36,  T.  31  N.,  R.  6  W.,  and  Sec.  31, 
T.  31  N.,  R.  5  W.  Area  of  holdings,  700  acres.  This  company  was 
organized  and  began  operations  in  the  summer  of  1900  on  a  flat  in 
Clear  Creek  caiion,  which  formerly  had  been  a  lake-bed.  The  bed- 
rock at  present  laid  bare  is  a  false  one,  under  which  probably  other 
gravel  will  lie  on  the  true  bedrock.  The  gravel,  which  is  20  feet  deep, 
is  a  loose,  clean  wash,  with  a  few  large  bowlders.  The  gold  is  coarse 
and  well  worn,  and  nearly  950  fine.  The  owners  state  that  the  value 
in  gold  per  cubic  yard  is  from  25  cents  to  $1.50,  with  a  little  platinum. 
Prospecting  was  done  by  sinking  shafts. 

The  dredge  was  designed  by  the  manager,  T.  R.  Heintz.  The  gravel 
is  raised  on  the  principle  of  the  hydraulic  elevator,  the  water  being 
forced  through  the  suction  pipe  by  a  centrifugal  pump,  and  with  the 
gravel  is  conveyed  in  a  stave  pipe  to  a  5-foot  sluice  paved  with  blocks. 
There  are  two  undercurrents  at  the  end  of  the  sluice.  The  manager 
estimates  the  average  cost  of  dredging  at  5  cents  per  cubic  yard.  The 
average  horse-power  consumed  is  750,  at  a  cost  of  $3,750  per  month. 
However,  the  amount  of  gravel  handled  is  placed  at  5,000  cubic  yards 
each  twenty-four  hours.     The  cost  of  the  plant  is  $100,000. 


CURRENT  BREAKERS  AND   CAISSONS   OF  THE  HURON   SUBMARINE  MIN- 
ING AND  CONSTRUCTION  COMPANY  AT  REDDING. 


ILL.    No.    59.      THE    HURON    SUBMARINE    MINING    AND     CONSTRUCTION    COMPANY' 
CAISSON  DREDGE  ON  SACRAMENTO  RIVER,  ABOVE  REDDING. 


102 


GOLD  DREDGING  IN  CALIFORNIA. 


TRINITY  COUNTY. 

The  only  dredge  iu  operation  is  at  Trinity  Center,  on  gravel  bars 
adjoining  the  Trinity  River ;  but  considerable  areas  of  gravel  have  been 
located  on  bars  along  the  river  with  a  view  to  dredging.  Of  this,  nearly 
2,000  acres  are  owned  by  two  companies— one  operating  and  the  other 
proposing  to  build  a  dredge.  There  are  along  the  river  many  bars  that 
probably  contain  sufficient  values,  but  a  majority  of  them  are  too  small 
for  the  cost  of  a  plant. 

Prospecting.— All  the  prospecting  has  been  done  by  sinking  shafts. 


ILL.  No.  «).     THK   GALVLX    GOLD    DRED(;ING    COMPANY 

COUNTY. 


)F   WKAVKRVILLE,  TRINITY 


Values. — The  values  are  not  evenly  distributed,  but  in  the  best  areas 
are  fair.     In  most  cases  15  cents  or  more  is  claimed. 

Gravel.— The  depth  of  the  gravel  varies  from  about  15  to  25  feeft. 
It  is  a  clean  wash,  comparatively  free  from  clay.  The  bowlders  are 
large  in  places,  but  there  are  not  enough  of  them  to  interfere  mate- 
rially with  the  work.     (See  111.  No.  61.) 

Bedrock.— The  bedrock  is  slate,  usually  hard  enough  to  interfere 
with  the  saving  of  coarse  gold. 

Pother.  — Steam. 

Waier.— Abundant. 


104 


GOLD  DREDGING  IN  CALIFORNIA. 


Labor.— y^^'uu-hnu'u,  $:{  lo  .^4;  lahoivrs.  $2.r)()  to  $:i. 

TranspoHaiion.—'By  team  from  Redding'. 

G'oid.— The  ^old  is  coarse,  a.s  is  also  the  phitinuni,  of  whicli  there  is 
considerable.  In  the  dredge  at  Trinity  Center,  one-inch  holes  are  used 
in  the  screen.     There  has  been  dredged  about  83  acres. 

The  problem  in  Trinity  County,  as  in  Siskiyou  County,  is  to  devise 
a  means  of  cutting  the  bedrock  or  cleaning  it.  A  large  proportion  of 
the  coarse  gold  is  on  the  bedrOTK,  or  in  it  in  crevices.  Excepting  in 
spots,  this  can  not  be  dredged  by  the  bucket  dredges  without  a  great 
deal  of  breaking  down  of  parts. 


ILL.  No.  ti2.    THE  POKER  BAR  DREDGE,  TRINITY  COUNTY.     RISDON  TYPE,  8^  CL.  FT. 
BUCKET  CAPACITY. 


COMPANIES   OPERATING. 

Alta  Bird  Mining  and  Dredging  Company,  Clary,  Payne  &  Kiernan, 
Trinity  Center.  In  Sees.  32  and  33,  T.  37  N.,  H.  7  W.,  and  Sees.  4  and 
5,  T.  36  N.,  R.  7  W.  Area  of  holdings,  687  acres.  This  company  began 
operations  April,  1901,  and  has  worked  5  acres.  It  has  one  31/2  cu.  ft. 
bucket  dredge  (Urie,  Kansas  City,  make),  and  contemplates  build- 
ing another,  or  putting  in  a  hydraulic  elevator. 

Trinity  Gold  Dredging  Company,  H.  G.  Comstock,  secretary,  San 
Franci>sco.  In  T.  33  N.,  R.  9  W.  Area  of  holdings,  1,100  acres.  On 
this  property  a  dredge  worked  30  acres  and  was  dismantled,  not  being 
strong  enough.     A  5  cu.  ft.  Monarch  bucket  dredge  is  now  proposed. 


GOLD  DREDGING  IN  CALIFORNIA.  105 

SISKIYOU  COUNTY. 

There  are  in  Siskivou  County  three  mines  being  worked  with 
livdraiilie  elevators-two  successfully  in  the  Oro  Fino  district  and  one 
in  (Quartz  Vallev.  One  Risdon  dredge  is  working  at  Callahan,  on 
Scott  River  A  Clipper  dredge  has  been  worked  at  Hawkmsville,  but 
is  not  now  in  operation,  and  one  on  the  Klamath  River,  which  is  also 

\s  in  nearlv  all  cases  in  the  mountain  districts  of  California,  the 
bedrock  is  harder  than  in  any  of  the  Sacramento  Valley  districts,  such 
as  Oroville,  Yuba,  and  Folsom.  It  has  so  far  been  found  almost  impos- 
sible to  work  bv  dredging,  for  the  hard  bedrock  prevents  the  clean 
saving  of  the  Amines,  and  breaks  the  bucket  and  other  parts  of  the 

ladder.  •  ■,  -,  ■  -^^ 

The  values  are  in  manv  cases  very  high,  but  as  the  gold  is  usually 
coarse  much  of  it  lies  on  the  bedrock.  So  far,  hydraulic  elevators 
seem  to  do  the  best  work  wherever  there  is  not  too  much  water  to 
prevent  cleaning  the  bedrock. 

The  area  of  gravel  in  this  county  now  being  worked  or  under  consid- 
eration bv  the  elevators  and  dredges  amounts  to  about  2,000  acres,  but 
there  is  much  more  that  would  be  exploited  if  more  successful  methods 
of  operation  could  be  devised. 

COMPANIES    OPERATING. 

^Ynght  &  Fletcher.  H.  D.  AVright  and  Mrs.  C.  D.  Frye,  Fort  Jones. 
In  Sec  18,  T.  43  N.,  R.  9  W.  In  the  Oro  Fino  Mining  District.  Area 
of  holdings,  200  acres.  This  company  began  operations  in  1890,  and 
has  worked  20  acres  of  ground.  The  values  are  not  given.  In  depth 
the  oravel  is  from  20  to  60  feet,  and  consists  largely  of  basaltic  angular 
fragments.  There  are  no  bowlders.  The  bedrock  is  soft  schists. 
Laborers  are  paid  $2.50  per  day.     The  gold  is  mastly  fine  and  worth 

i^l6  per  ounce. 

This  mine  is  being  worked  with  an  Evans  hydraulic  elevator,  with  an 

outlet  pipe  20  inches  in  diameter.     The  lift  is  20  feet.     The  pressure 

pipe  is  11  inches  in  diameter,  with  a  head  of  11  feet.     The  flume  is 

3  feet  wide,  with  block  paving. 

EasiUck  &  Gardner.  L.  Eastlick,  of  Fort  Jones,  and  S.  Gardner, 
of  Greenview.  In  Sec.  17,  T.  13  N..  R.  9  W.,  in  the  Oro  Fino  Mining 
District  Area  of  holdings,  25  acres.  This  company  began  operations 
in  1890  and  has  worked  8  acres.  The  values  are  not  given.  In  depth 
the  -ravel  is  from  25  to  40  feet,  and  consists  largely  of  schist  and 
porphyrv  in  fragments  which  are  not  much  rounded.  There  are  no 
bowlders.  The  bedrock  is  mostly  soft  slate.  Laborers  receive  $2.o0 
per  day.     The  ^old  is  mostly  fine  and  worth  $16.25  per  ounce. 


J 


106 


GOLD  DHEDGING  IN  CALIFORNIA. 


This  mine  is  being  worked 
with  two  Evans  elevators. 
One  has  a  22-inch  outlet  pipe, 
a  lift  of  32  feet,  and  a  15- 
inch  pressure  pipe  with  a 
head  of  300  feet.  The  other 
has  an  outlet  pipe  13  inches 
in  diameter,  the  lift  is  32 
feet,  and  the  pressure  pipe 
is  13  inches  in  diameter  with 
a  head  of  300  feet.  The 
flumes  are  24  inches  wide, 
with  block  pavements  and 
Hungarian  riffles. 

Porters  Bar  Dredging 
Company,  J.  R.  Wade,  gen- 
eral superintendent,  Calla- 
han. In  Sees.  6,  7,  and  17, 
T.  40  N.,  R.  8  W.,  below  Cal- 
lahan, on  Scott  River.  Area 
of  holdings,  1,000  acres. 
The  dredge  of  this  company 
has  been  at  work  in  the  Scott 
River,  below  Callahan,  for  a 
number  of  years,  but  was 
purchased  by  the  present 
company  in  the  summer  of 
1904,  when  it  also  acquired 
larger  holdings  below  the 
present  workings.  The  new 
company  has  made  an  exam- 
ination of  its  property  with 
drills,  checked  by  shafts 
sunk.  The  values  are  not 
given.  In  depth  the  gravel 
averages  about  36  feet,  and 
varies  considerably  in  char- 
acter of  material,  there  being- 
many  large  bowlders,  mak- 
ing an  open  connection  of 
buckets  necessary.  The  bed- 
rock varies,  some  being  shale, 
but   mostly   hard   greenstone. 


GOLD  DREDGING  IN  CALIFORNIA, 


107 


Electric  power  generated  by  water  power  belonging  to  the  company 
is  used.  The  amount  consumed  in  the  dredge  is  100  horse-power,  which 
costs  $2  per  horse-power  per  month.  There  is  an  abundance  of  cheap 
water  in  all  this  country.  Wages  are  $3  for  winchmen,  and  $2.25  and 
$2.50  for  ordinary  laborers.  Transportation  is  by  rail  from  San 
Francisco,  337  miles,  and  by  team  over  reasonably  good  roads,  25  miles 
from  Gazelle.  Scott  Valley  furnishes  food  supplies  at  low  rates.  The 
gold  is  coarse  and  worth  from  $17  to  $18  per  ounce.  No  platinum 
is  found. 


ILL.  No.  &l.    CONSOLIDATED  MINING  AND  DREDGING  COMPANY'S  DREDGE  AND  CAIS- 
SON—THE CAISSON  SHOWS  AT  STERN  OF  DREDGE.    SISKIYOU  COUNTY. 

The  company  proposes  to  have  the  dredge  dig  its  own  channel  down 
the  river  over  a  mile  to  where  the  bedrock  is  softer.  The  dredge  is  of 
the  Risdon  type,  with  5  cu.  ft.  bucket  capacity,  and  the  owners  are 
at  present  making  some  modifications,  particularly  as  to  the  bucket  line, 
on  account  of  the  hardness  of  bedrock.  The  buckets  are  to  be  made 
much  stronger,  with  lips  heavier  than  is  usual.  These  are  8  inches 
wide,  and  weigh  about  140  pounds,  against  the  usual  90  pounds,  and 
protrude  about  2  inches  beyond  the  bucket.  The  links  on  which  the 
buckets  are  placed  are  6i4  inches  deep  and  are  connected  by  234-inch 
pins.  These  links  are  26  inches  between  center  pins.  The  sides  of 
the  tumbler  are  211/2  inches. 


U)S  IHM.P    1>KK1H!IN^;    IN     C  \1  1  KOU  N  I  A. 

Y  rtkii  Citd,-  Hold  />/■((/<//;((;  ('otnihinii.  (\cov)Xc  A.  1  .ouiisIhmtn-. 
Oi'oan  Tark.  Los  AnL^rK-s  rounty.  In  T.  }.'>  X..  K,  7  \V.  Ai^\i  o( 
lu>Uliuii>i,  -00  ;u'ros.  Oporalioiis  wimh'  i'omnuMU'(\l  u\  IS!'!',  with  ;i  siuizlo 
dippor  ilroilui".  Init  oiilsulo  of  [he  A\p\^cr.  \\w  msialhition  to  luiuillo  lt\o 
i^T.-ivol  I'onsists  ot'  two  iilontu'al  plants,  one  on  oat'h  sulo  o\'  \\\c  Avcdixc. 
Spuils  aro  usoil  for  holduii:-  fho  Invit  ni  pla^'o,  'Vhc  liippor.  of  1  oubio 
yard  i.'apa<.'Uy.  iluuips  on  a  rt^volvniu'  s^'roon  IS  foot  lon^-.  with  l-nioh 
Itolos  in  tlio  tit-st  U^  foot  and  >  •_-  moh  holos  in  tho  routainiiii:-  S  foot. 
Tho  sluioiui;"  tablos  afo  pfovidi\l  with  burlap  and  w  iro-niosh  i-itllos. 
toiivthor  witli  sUnoo  boxos.  '^0  mohos  w  ido.  with  Uunu-afian  riitlos.  A 
Iniokot  staokoi-  is  nsod  It  is  olaiiuod  that  iindor  fav(M-ablo  oonditions 
tho  drodiTO  oan  handU>  \.\00  oubii*  yards  daily,  ('•wini:  lo  hard  bodrook. 
tliofo  woiv  oontinnal  bvoakdow  ns  and  tho  drodi^o  i^  now  idU\  ^See 
III.  No.  ti;>.^ 

Klamath  Eher  Gold  Mimvp  C(>mpa in/.  rL  A.  Fostor.  prosidont.  Biuu-s. 

In  Sw.  22.  T.  46  "N..  H.  T  \V..  on  tlie  KUamath  Kivor.  .\roa  of  holdmirs. 
77  aeivis.  This  oompany  boizan  oporations  in  -Inno.  UHU.  witli  a  dtvdiro 
dosijrnod  by  Mr.  l-'ronoli.  It  is  a  steam-shovol  droo.iio.  but  tho  buoket 
d<.vs  not  work  on  a  boom,  it  boiuii'  lUiU'od  by  two  stool  oablos.  This 
company's  pivpovty  is  on  (..arvoy's  Ivir.  on  il\o  Klamath  Kivor.  a  littlo 
rtboYo  the  month  of  llumlnii:'  Orook.  The  avora^o  dopth  of  Uio  iiravol 
is  tiO  feet,  lyin^  on  a  medium  hard  slate.  It  is  eotuise  and  there  aro 
niaiix'  lai"ge  bo\YUiei*s.  It  is  a  blue  iiravel.  with  snlphnivts.  but  withou! 
blaek  sand.  Tlie  ^^Id  is  UK>stlY  tine,  and  worth  about  !^17,80  per  oiinoo. 
Waires  ai-e  $4  for  the  engineer,  and  $2  for  labonM*s.  Steam  powor 
ovists  5^o  per  hoi'st^-power  per  month.  .\t  pn>sent  the  di*eil^^  is  uot 
boiuiT  operated. 

-1.  (\  Brokaw,  Fort  doues,  is  operating  an  hydraulie  elevator  in 
Quartx  Valley.  It  is  of  the  Henti\-  type,  of  2t^  inehes  diameter,  with 
6-ineh  noxjile.  ^Yith  1.5(.K>  inehes  of  water  under  230  feet  of  pressure. 
the  owner  ivports  that  2,5W  enbie  yanls  of  jriiwel  is  raised  30  feet  in 
twenty- four  houi"s. 


APPENDIX. 


CALIFORNIA  STATE  MINING  BUREAU. 


This  institution  aims  to  be  the  chief  source  of  reliable  information 
about  the  mineral  resources  and  mining  industries  of  California. 

It  is  encouraged  in  its  work  by  the  fact  that  its  publications  have 
been  in  such  demand  that  large  editions  are  soon  exliausted.  In  fact, 
copies  of  them  now  command  high  prices  in  the  market. 

The  publications,  as  soon  as  issued,  find  their  way  to  the  scientific, 
public,  and  private  libraries  of  all  countries. 

STATE  MINERALOGIST. 

The  California  State  ]\Iining  Bureau  is  under  the  supervision  of 
Hon.  Lewis  E.  Aubury,   State  ^Mineralogist. 

It  is  supported  by  legislative  appropriations,  and  in  some  degree 
performs  work  similar  to  that  of  the  geological  surveys  of  other  States ; 
but  its  purpasas  and  functions  are  mainly  practical,  the  scientific  work 
being  clearly  subordinate  to  the  economic  phases  of  the  mineral  field, 
as  shown  by  the  organic  law  governing  the  Bureau,  which  is  as  follows : 

Sec.  4.  It  shall  be  the  duty  of  said  State  Mineralogist  to  make,  facilitate,  and 
encourage  special  studies  of  the  mineral  resources  and  mineral  industries  of  the 
State.  It  shall  be  his  duty  :  To  collect  statistics  concerning  the  occurrence  of  the 
economically  important  minerals  and  the  methods  pursued  in  making  their  valu- 
able constituents  available  for  commercial  use :  to  make  a  collection  of  typical 
geological  and  mineralogical  specimens,  especially  those  of  economic  or  commercial 
importance,  such  collection  constituting  the  Museum  of  the  State  Mining  Bureau ; 
to  provide  a  library  of  books,  reports,  drawings,  bearing  upon  the  mineral  industries, 
the  sciences  of  mineralogy  and  geology  and  the  arts  of  mining  and  metallurgy,  such 
library  constituting  the  Library  of  the  State  Mining  Bureau  ;  to  make  a  collection 
of  models,  drawings,  and  descriptions  of  the  mechanical  appliances  used  in  mining 
and  metallurgical  processes  :  to  preserve  and  so  maintain  such  collections  and  library 
as  to  make  them  available  for  reference  and  examination,  and  open  to  public  inspec- 
tion at  reasonable  hours ;  to  maintain,  in  effect,  a  bureau  of  information  concern- 
ing the  mineral  industries  of  this  State,  to  consist  of  such  collections  and  library, 
and  to  arrange,  classify,  catalogue,  and  index  the  data  therein  contained,  in  a 
manner  to  make  the  information  available  to  those  desiring  it,  and  to  provide  a 
custodian  specially  qualified  to  promote  this  purpose ;  to  make  a  biennial  report  to 
the  Board  of  Trustees  of  the  Mining  Bureau,  setting  forth  the  important  results 
of  his  work,  and  to  issue  from  time  to  time  such  bulletins  as  he  may  deem 
advisable  concerning  the  statistics  and  technology  of  the  mineral  industries  of  this 
State. 

THE  BULLETINS. 

The  field  covered  by  the  books  issued  under  this  title  is  shown  in 
the  list  of  publications.  Each  bulletin  deals  with  only  one  phase  of 
mining.  ]\Iany  of  them  are  elaborately  illustrated  with  engravings 
and  maps.  Only  a  nominal  price  is  asked,  in  order  that  those  who 
need  them  most  may  obtain  a  copy. 


112  CAIJPORNIA    STATE    MINING    BUREAU. 


THE  REGISTERS  OF  MINES. 


The  Registers  of  Mines  form  practically  both  a  State  and  a  County 
directory  of  the  mines  qf  California,  each  county  being  represented  in 
a  separate  pamphlet.  Those  who  wish  to  learn  the  essential  facts  about 
any  particular  mine  are  referred  to  them.  The  facts  and  figures  are 
given  in  tabular  form,  and  are  accompanied  by  a  topographical  map  of 
the  county  on  a  large  scale,  showing  location  of  each  mineral  deposit, 
towns,  railroads,  roads,  power  lines,  ditches,  etc. 

HOME  OF  THE  BUREAU. 

The  Mining  Bureau  occupies  the  north  half  of  the  third  floor  of 
the  Ferry  Building,  in  San  Francisco.  All  visitors  and  residents  are 
invited  to  inspect  the  Museum,  Library,  and  other  rooms  of  the  Bureau 
and  gain  a  personal  knowledge  of  its  operations. 

THE  MUSEUM. 

The  Museum  now  contains  over  16,000  specimens,  carefully  labeled 
and  attractively  arranged  in  showcases  in  a  great,  well-lighted  hall, 
where  they  can  be  easily  studied.  The  collection  of  ores  from  Cali- 
fornia mines  is  of  course  very  extensive,  and  is  supplemented  by  many 
cases  of  characteristic  ores  from  the  principal  mining  districts  of  the 
world.  The  educational  value  of  the  exhibit  is  constantly  increased 
by  substituting  the  best  specimens  obtainable  for  those  of  less  value. 

These  mineral  collections  are  not  only  interesting,  beautiful,  and  in 
every  way  attractive  to  the  sightseers  of  all  classes,  but  are  also  educa- 
tional. They  show  to  manufacturers,  miners,  capitalists,  and  others 
the  character  and  quality  of  the  economic  minerals  of  the  State,  and 
where  they  are  found.  Plans  have  been  formulated  to  extend  the 
usefulness  of  the  exhibit  by  special  collections,  such  as  one  showing  the 
chemical  composition  of  minerals;  another  showing  the  mineralogical 
composition  of  the  sedimentary,  metamorphic,  and  igneous  rocks  of  the 
State;  the  petroleum-bearing  formations,  ore  bodies,  and  their  country 
rocks,  etc. 

Besides  the  mineral  specimens,  there  are  many  models,  maps,  photo- 
graphs, and  diagrams  illustrating  the  modern  practice  of  mining, 
milling,  and  concentrating,  and  the  technology  of  the  mineral  indus- 
tries. An  educational  series  of  specimens  for  high  schools  has  been 
inaugurated,  and  new  plans  are  being  formulated  that  will  make  the 
]\Iuseum  even  more  useful  in  the  future  than  in  the  past.  Its  popu- 
larity is  shown  by  the  fact  that  over  100,000  visitors  registered  last 
year,  while  many  failed  to  leave  any  record  of  their  visit. 


8— GD 


114  CALIFORNIA    STATE    MINING    BUREAU. 

THE  LIBRARY. 

This  is  the  mining  reference  library  of  the  State,  constantly  con- 
sulted by  mining  men,  and  contains  between  4000  and  5000  volumes 
of  selected  works,  in  addition  to  the  numerous  publications  of  the 
Bureau  itself.  On  its  shelves  will  be  found  reports  on  geology,  min- 
eralogy, mining,  etc.,  published  by  states,  governments,  and  indi- 
viduals ;  the  reports  of  scientific  societies  at  home  and  abroad ; 
encyclopaedias,  scientific  papers,  and  magazines;  mining  publications; 
and  the  current  literature  of  mining  ever  needed  in  a  reference  library. 

Manufacturers'  catalogues  of  mining  and  milling  machinery  hy 
California  firms  are  kept  on  file.  The  Registers  of  Mines  form  an 
up-to-date  directory  for  investor  and  manufacturer. 

The  librarian's  desk  is  the  general  bureau  of  information,  where 
visitors  from  all  parts  of  the  world  are  ever  seeking  information  about 
all  parts  of  California. 

READING-ROOM. 

This  is  a  part  of  the  Library  Department  and  is  supplied  with  over 
one  hundred  current  publications.  Visitors  will  find  here  various 
California  papers  and  leading  mining  journals  from  all  over  the  world. 

The  Library  and  Reading-Rpom  are  open  to  the  public  from  9  a.  m. 
to  5  p.  M.  daily,  except  Sundays  and  holidays. 

THE  LABORATORY. 

This  department  identifies  for  the  prospector  the  minerals  he  finds, 
and  tells  him  the  nature  of  the  wall  rocks  or  dikes  he  may  eiLcounter 
in  his  workings;  but  this  department  does  not  do  assaying  nor  compete 
with  private  assayers.  The  prasence  of  minerals  is  determined,  but 
not  the  percentage  present.  No  charges  for  this  service  are  made  to 
any  resident  of  the  State.  Many  of  the  inquiries  made  of  this  depart- 
ment have  brought  capital  to  the  development  of  new  districts.  Many 
technical  questions  have  been  asked  and  answered  as  to  the  best 
chemical  and  mechanical  processes  of  handling  ores  and  raAv  material. 
The  laboratory  is  well  equipped. 

THE  DRAUGHTING-ROOM. 

In  this  room  are  prepared  scores  of  maps,  from  the  small  ones  filling 
only  a  part  of  a  page,  to  the  largest  County  and  State  maps;  and  the 
numerous  illustrations,  other  than  photographs,  that  are  constantly 
being  required  for  the  Bulletins  and  Registers  of  Mines.  In  this  room, 
also,  will  be  found  a  very  complete  collection  of  maps  of  all  kinds 
relating  to  the  industries  of  the  State,  and  one  of  the  important  duties 
of  the  department  is  to  make  such  additions  and  corrections  as  will 
keep  the  maps  up  to  date.  The  seeker  after  information  inquires  here 
if  he  wishes  to  know  about  the  geology  or  topography  of  any  district ; 
about  the  locations  of  the  ncAV  camps,  or  positions  of  old  or  abandoned 


116 


CATJFORXIA    STATE    MINING    BUREAU. 


ones;  about  railrdnds,  stauo  I'oads,   and  trails;  or  about  the   woi-king 
drawing's  of  anylliinu'  conncctod  with  mining. 

MINERAL  STATISTICS. 

One  of  the  features  of  this  institution  is  its  mineral  statistics.  Theii- 
annual  compilation  by  the  State  Mining  Bureau  began  in  1893.  No 
other  State  in  the  Union  attempts  so  elaborate  a  record,  expends  so 
much  hibor  and  money  on  its  compilation,  or  .secures  so  accurate  a  one. 

The  State  Mining  Bureau  keeps  a  careful,  up-to-date,  and  reliable 
but  confidential  i-egister  of  every  producing  mine,  mine-owner,  and 
mineral  industry  in  the  State.  From  them  are  secured,  under  pledge 
of  secrecy,  reports  of  output,  etc.,  and  all  other  available  sources  of 
information  are  used  in  checking,  verifying,  and  supplementing  the 
information  so  gained.  This  information  is  published  in  an  annual 
tabulated,  statistical,  single-sheet  bulletin,  showing  the  mineral  pro- 
duction by  both   substances   and   counties. 

TOTAL  GOLD  PRODUCT  OF  CALIFORNIA-1848-1903. 


1848... 
1849  . 
1850... 
1851... 
1852-  . 


:|;'245.S(i 


81,294,701) 


185.3 67,613,487 

1854 69,433,931 

1855 55,485,395 

1856 57,509,411 


1857. 
1858. 
1859. 
1860- 
1861. 
1862. 


43,628,172 
46,591.140 
4."'>,s4(;..">'.i!) 
44, (lit:..  It;:; 
41,884,995 
38,854,668 


$2H,5()i,7;v; 


18,265,452 
17,555,867 
18,229,044 
17,458,1.33 

1871 17,477,885 

1872 15,482,194 

1873 15,019,210 

1874 17,2tU,s;;t; 

1875 16,K7<;,n(i:i 

1876.  15,(ilO,723 

1877.  ...  16,501,268 


1867. 
1868- 
1869. 
1870. 


1882.. 
1883. 
1884- 
1885- 
1886. . 
1887. 
ISS.S.. 
issi). 

IS'.MI.. 
1891. 
1892- 


17,146,41(i 
24,316,873 
13,(!()0,0(l0 
12, (it;  I, (144 

i4,7i(;,.'i(it; 
i;i,:>ss.(;i4 

ILL'lLV'lH 

I2,:;(i!i,793 

12,728,869 
12,571,900 


lWt3. 

1S!)4. 


1S97 
189S 
IS99. 
19(1(1 


$12,422,811 
13,923,2SI 
15,.334,317 
17,181,-562 
15,871,4(11 
15,9(Ni,47S 

i5,3:-!6,(i;;i 

15,8(i3,:5.'i.") 
16,9S9,(144 
16,910,320 
16,471,264 


il--!t!l,.395,746,672 


COUNTY  RANK   IN  GOLD  PRODUCT  IN   1903. 

"While  gold  is  still  the  leading  mining  product,  its  yield  no  longer 
puts  the  greatest  gold-producing  county  in  the  first  place.  The  petro- 
leum of  Kern  County  and  the  copper  of  Shasta  give  them  precedence. 
Gold  is  more  widely  distributed  than  any  other  substance  thus  far 
mined  in  California ;  34  counties  out  of  the  57  in  the  State  showing  a 
gold  yield  in  1903,  and  it  is  known  to  exist  in  several  others.  The  order 
in  rank  of  the  counties  of  the  State,  in  the  production  of  gold  alone, 
is  at  present  as  follows : 


1. 

Nevada..   .. 

...$2,4.58,047 

13. 

Plumas 

$424,112 

25. 

Fresno $21,5.38 

2 

Calaveras... 

...  1,904,125 

14. 

S.  Bernardino 

.381.197 

26. 

Eiverside 13,4.53 

3. 

Tuolumne . . 

...   1,732,.572 

15. 

Sacramento  .. 

.•!:ri.646 

Tulare-- 9,215 

4. 

Amador    

...  1,609,744 

16. 

Mono . 

:;.';i.7i:; 

•^s. 

Monterev s,92o 

5. 

Butte 

-.     1,. 571, 507 

17. 

Sierra  

:;|ii.77() 

:':i. 

Los  Angeles...          8,674 

6. 

Kern 

.  ..    1.022,3.53 

18. 

El  Dorado  .-. 

277,304 

;-;(i. 

Del  Norte 7,1S3 

7 

Shasta 

...       771,242 

19. 

Yuba 

125,830 

31. 

Alpine 2,701 

8. 

Siskiyou  ... 

...       t!13,57ti 

20. 

Madera 

93,070 

32. 

San  Luis  Obispo         1,840 

9. 

Trinitv    -.   - 

607, 72X 

21. 

Lassen  . 

91,102 

33. 

Ventura  .  . 1,087 

10. 

Placer  .    ... 

..       570,571 

00 

Invo 

66,045 

34. 

Orange    .....          ,     1,50 

11. 

Mariposa 

.       ,542,3,V) 

23. 

Stanislaus     .. 

-  .52,869 

12. 

San  Diego  . 

...      461,516 

24. 

Humboldt     .- 

38,.509 

Total .$16,471,264 

118  CALIFORNIA    STATE    MINIXG    BUREAU. 

TOTAL  MINERAL  PRODUCT  OF  CALIFORNIA   FOR   1903. 

The  following  table  shows  the  yield  and  value  of  mineral  substances 
of  California  for  1903,  as  per  returns  received  at  the  State  Mining 
Bureau,  San  Francisco,  in  answer  to  inquiries  sent  to  producers : 

Quantity.  Value. 

Asphalt - 41,670tons  $503,659 

Bituminous  Rock 21,944     "  63,106 

Borax  (Crude) 34,430    "  661,400 

Cement 640,868  bbls.  968,727 

Chrome. 150  tons  2,250 

Chrysoprase    .. 500 

Clays:  For  Pottery... 90,972  tons  99,907 

For  Brick 214,403  M  1,999,546 

Coal 93,026tons  265,383 

Copper ._.,lit,113,S611bs.  2,520,997 

Fuller's  Earth.. 250  tons  4,750 

GlassSand .          7,725    "  7,525 

Gold 16,471,264 

Granite 408,625  cu.  ft.  678,670 

Gypsum    6,914  tons  46,441 

Infusorial  Earth 2,703     "  16,015 

Lead... 110,000  lbs.  3,960 

Lime- .    ___-      496,587  bbls.  418,280 

Limestone 125,919  tons  163,988 

Lithia  Mica 700    "  27,300 

Macadam ...      6t)5,185    "  436,172 

Manganese 1     "  25 

Magnesite    1,361    "  20,515 

Marble.. 84,624  cit.  ft.  97,354 

Mica oOtons  3,800 

Mineral  Paint 2,370    "  3,720 

Mineral  Water  _...  1,978,340  gals.  558,201 

Natural  Gas 120,134  M  cu.  ft.  75,237 

Paving  Blocks..- 4,854  M  134,642 

Petroleum    24,340,839  bbls.  7,313,271 

Platinum.    ....    1,052 

Pyrites.   24,311  tons  94,000 

Quartz  Crystals 1,968 

Quicksilver 32,094  flasks  1,335,954 

Rubble 1,610,440  tons  1,237,419 

Salt. .- -- 102,895     "  211,365 

Sandstone 353,002  cu.  ft.  585,309 

Serpentine 99"    "  800 

Silver - 517,444 

Slate - 10,000  squares  70,000 

Soapstone ..    .     219  tons  10,124 

Soda 18,000    "  27,000 

Tourmaline. 100,000 

Turquoise    ..  .- - .   10,000 

Total  value |.37,759,040 


CALIFORNIA   STATE    MININ(;    BUREAl^ 


119 


RELATIVE  RANK  OF  COUNTIES  IN   TOTAL  MINERAL  PRODUCT  IN  1903. 


1.  Kern $4,957,602 

2.  Shasta 8,201,680 

3.  Los  Angeles...  2,54H,12S 

4.  Nevada   2,4»;(>.(i44 

6.  Calaveras 2,27u,6t).s 

6.  Tuolumne l,7i»l,(i."i(i 

7.  Amador 1,639,819 

8.  Butte 1,581,325 

9.  San  Bernardino  1,516,618 

10.  Orange 1,029,435 

11.  Napa 896,848 

12.  Fresno 848,628 

13.  San  Francisco.      802,786 

14.  Placer.. 8(M),985 

15.  Ventura 714,766 

16.  Santa  Clara..  .      670,159 

17.  Siskivou 663,598 

18.  San  Diego 663,315 

19.  Trinity 621,244 


Mariposa 

Alameda 

Sacramento .-. 

^ladera 

Riverside 

Plumas  .-- 

Colusa 

Solano  ... 

Santa  Barbara - 
San  Benito. .  . 

Mono . 

Sierra 

Lake 

El  Dorado 

S'n  Luis  Obispo 

Santa  Cruz 

San  Mateo 

Marin 

Sonoma . 


1552,516  i 
530,207 
50(5,796 
489,525 
446,449 
424,894 
420,468 
404,614 
384,688 
367,851 
360,024 
311,246 
2i»4,018 
284,304  j 
257,416 
254,247  i 
252,500 
218,427  1 
195,369  I 


Invo 11.39,563 

Yuba 125,871 

Lassen   92,305 

Stanislaus    ...  70,605 

Contra  Costa.  62,500 

Monterey. 51,436 

Humboldt    ...  49,31(i 

San  Joaquin  _  44,4X9 

Tulare    ..   ...  41,175 

Kings  ._    ...  24,200 

iSlendocino  .__  20,580 

Del  Norte 7,183 

Tehama 7,000 

Alpine 2,847 

Yolo 144 

Merced 780 

Unapportioned  377,783 

Total 137,759,040 


MINING  BUREAU  PUBLICATIONS. 

Publications  of  this  Bureau  will  be  sent  on  receipt  of  the  requisite 
amount  and  postage.  Only  stamps,  coin  or  money  orders  will  be 
accepted  in  payment.     {All  puhlications  not  mentioned  are  exhausted.) 

Attention  is  respectfully  called  to  that  portion  of  Section  8,  amend- 
ment to  the  IMining  Bureau  Act,  approved  ]\Iarch  10,  1903,  which  states : 

"The  Board  (Board  of  Trustees)  is  hereby  empowered  to  fix  a  price 
upon,  and  to  dispose  of  to  the  public,  at  such  price,  any  and  all  pub- 
lications of  the  Bureau,  including  reports,  bulletins,  maps,  registers, 
etc.  The  sum  derived  from  such  disposition  must  be  accounted  for  and 
used  as  a  revolving  printing  and  publishing  fund  for  other  reports, 
bulletins,  maps,  registers,  etc.  The  prices  fixed  must  approximate 
the  actual  cost  of  printing  and  issuing  the  respective  reports,  bulletins, 
map.s,  registers,  etc.,  without  reference  to  the  cost  of  obtaining  and 
preparing  the  information  embraced  therein." 

Prioe.  Postage. 

Report  XI— 1892,  First  Biennial $100  .$0  15 

Report  XIII— 1896,  Third  Biennial 100  20 

Bulletin  No.    5 — "Cyanide  Process"  (4tli  edition),  bound 60  08 

Bulletin  No.    6— "Gold  Mill  Practices  in  California"  (3d  edition) .50  04 

Bulletin  No.    9 — "Mine  Drainage,  Pumps,  etc.,"  bound 60  08 

Bulletin  No.  15— "Map  of  Oil  City  Oil  Fields,  Fresno  County,  Cal." 05  02 

Bulletin  No.  16 — "Genesis  of  Petroleum  and  Asphaltum  in  California," 

(3d  edition) - 30  03 

Bulletin  No.  18 — "Mother  Lode  Region  in  California" 35  06 

Bulletin  No.  23— "Copper  Resources  of  California" 50  *      12 

Bulletin  No.  24— "Saline  Deposits  of  California" .50  10 

Bulletin  No.  27— "Quicksilver  Resources  of  California" 75  08 

Bulletin  No.  30 — "Bibliography  Relating  to  the  Geology,  Palaeontology 

and  Mineral  Resources  of  California,  including  List  of  Maps" .50  10 

Bulletin  No.  31— "Chemical  Analyses  of  California  Petroleum" ...  02 

Bulletin  No.  32— "Production  and  Use  of  California  Petroleum" 75  08 

Bulletin  No.  33— "Mineral  Production  of  California— 1903" __.  02 


120  CALIFORNIA   STATE    MINING   BUREAU. 

Price.  Postage. 

Bulletin  No.  34— "Mineral  Production  of  California  for  17  Years" |0  02 

Bulletin  No.  35— "Mines  and  Minerals  of  California" _..  04 

Map  of  Mother  Lode !fO  05  02 

Gold  Production  in  California  from  1848  to  1904__ _,.  02 

Register  of  Mines,  with  Map,  Plumas  County 25  08 

Register  of  Mines,  with  Map,  Siskiyou  County 25  08 

Register  of  Mines,  with  Map,  Trinity  County ...      25  08 

Register  of  Mines,  with  Map,  Lake  County 25  08 

Register  of  Mines,  with  Map,  Nevada  County 25  08 

Register  of  Mines,  with  Map,  Placer  County... 25  08 

Register  of  Mines,  with  Map,  El  Dorado  County 25  08 

Register  of  Mines,  with  Map,  Inyo  County 25  08 

Register  of  Mines,  with  Map,  Shasta  County 25  08 

Register  of  Mines,  with  Map,  San  Bernardino  County. 25  08 

Register  of  Mines,  with  Map,  San  Diego  County 25  08 

Register  of  Mines,  with  Map,  Sierra  County 25  08 

Register  of  Mines,  with  Map,  Amador  County.   25  08 

Register  of  Mines,  with  Map,  Tuolumne  County 25  08 

Register  of  Mines,  with  Map,  ButteCounty.. 25  08 

Register  of  Mines,  with  Map,  Mariposa  County 25  08 

Register  of  Mines,  with  Map,  Kern  County   25  08 

Register  of  Oil  Wells,  with  Map,  Los  Angeles  City 35  02 

Relief  and  Mineral  Map  of  California 25  05 

Map  of  Calaveras  County 25  08 

In  Preparation : 

Gems  and  Jewelers' Materials  of  California  . . 

Structural  and  industrial  ^Materials  of  California ... 

Samples  of  any  mineral  found  in  the   State  may  be  sent  to  the 
Bureau  for  identification,  and  the  same  will  be  classified  free  of  charge. 

It  must  be  understood,  however,  that  no  assays,  or  quantitative  deter- 
minations, ivill  he  7nade.  Samples  should  be  in  lump  form  if  possible, 
and  the  outside  of  package  should  be  marked  plainly  with  name  of  • 

sender,  postoffice  address,  etc.,  and  a  stamp  should  be  inclosed  for  reply. 


l.L,sraH>^i 


IHRH 


'IK 


DREDGE  LOCATIONS 

/V9 1.  dredge:  of  folsom  dev.  co 


4.  TOWN  OF  dredge"  FD£U  CO. 

5.  F DEV.  CO.   (/3^  hucMefdredse) 

6.  SYNDIC/^TE    DREDGE  CO. 

7.  S/ilLOR  B/iR'/)SHBURTON  D.  CO 
a.  F DEI/ CO  (/jft  buo/fef  driLdga) 
9.  EL   DOR/iOO   GOLD  D    CO 


ILL.  No,  Oil.     FIELD  OF  OPERATIONS  IN  FOLSOM  DISTRICT,  SHOWING  LOCATIONS  OF  DREDGING  COMPANI 


pAcr  c^oaanci 


ooo.oj^' 


!Q§*'.     .'ilui 


1  {■  .a    .Xt!!  .1  .c,i:  .it  .'■:• 


DREDQE    DATA   ACCOMPANYINQ    BULLETIN    No.    36=-= 

Issued  by  the  State  Mining  Bureau,  Ferry  Building,  San  Francisco.     LEWIS  E.  AUl 


o.    36==-"  DREDGE    MINING 

LEWIS  E.  AUBURY,  State  Mineralogist,  1905. 


IN    CALIEORNIA." 


Revolving. 

Revolving. 

Revolving. 

Revolving. 

Shaking. 

Shaking. 

Revolving. 

Shaking. 

Revolving. 

Shaking. 

Revolving. 

Revolving. 

Shaking. 

Shaking. 

Shaking. 

Shaking. 


Shaking. 
Revolving. 


Qold-Saving  Tables. 


Cocoa  matting  and 

expanded  metal. 
Cocoa  matting  and 

expanded  metal. 
Cocoa  matting  and 

expanded  metal. 
Cocoa  matting  and 

expanded  metal. 
Riffles. 


}  Bucket. 
(  Bucket. 
i  Bucket. 
Belt. 


Riffles. 


Cocoa  matting 

expanded  me 

Riffles. 


Revolving.  | 
Revolving,  j 


Shaking. 

Revolving. 

Revolving. 

Shaking. 

Shaking. 

Shaking. 

Revolving. 

Revolving. 


Revolving. 


I  Bucket. 


Electric. 
Hectric. 


Electric. 
Electric. 


(  Bucket. 


expanded  metal. 

expanded  metal. 
Cocoa  matting  and 
expanded  metal. 


Riffles.  I    Belt. 

Cocoa  matting  and  It  „„„,,„, 

expanded  mital.    }  Bucket. 
Cocoa  matting  and  I  n„„i,„* 

expanded  mStal.  1}  Bucket. 

- I    Belt. 


Cocoa  matting  and 
expanded  metal. 


Belt. 


Riffles. 


Cocoa  matting  and 

expanded  metal. 

Riffles. 

Cocoa  matting  and 
expanded  metal. 


Electric. 
Electric, 
tlcctric. 
Electric. 
Electric. 
Electric. 
Electric. 
Electric. 
Electric. 
Electric. 


Electric. 
Electric. 
Electric. 

Electric. 
Electric. 


-      ) 


cperK.VV. 


(       75,000 
50,000 


36,000 
50,000 


90,000 
60,000 
60,000 


I     35,000 
60,000 


(     80,000 


120,000 
90,000 


30,000 
65,000 


Shafts  and  drill. 

Drill 

Drill 

Drill 

Drill 


DrUl... 
Drill  .. 
Shafts  . 
Drill... 


The  first  successful  dredge  in  ( 


,  KA     1  Cost  Of  equipment  includes   in 

1      pump  station. 
!  50       •Oolden  Slate  and  Miners'  I  ron 


I  There  were  no  breakdowns,  no  repair  cost 

I      dredge.    Exceptional  case. 

I  'Lmk  Belt  Machinery  Co.,  builders.  Pew  h 

f      sampling. 

,  -Cost  of  power  for  12  months,  |8.3m.0O. 


•per  hour     fZ 


Shafts  und  pipes  j| 


treason  r«biiiliHng dredge. 


One-inch  holes  in  screen.     May.  instead  o 
dredge,  use  hydraulic  elevator. 
Uata  from  old  dredge,  now  dismantled.    Nc 
(Monarch)  building. 


Remodeling  dredge,  owing  to  conditions  dilTerent 


Many  sulplmrets  but  no 
Formerly  Souther  dredg 
Evans  hydraulic  elevatt 
One  Martin  hydrauli 
hydraulic  elevator. 


IV 1/1  .nijiaiBH  .L  .' 

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i.f/uiO  ,,i^l(C  .q■iau^...ll   ''» 


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....  ..oO  aofisinfqxa  isvi^I  lorij  .'• 

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oO  sniaiM  bfiB  j^nijih-jitl  bl<. 

...<>'>  ynhifM  •■lIivti^-iUbiU2  tiulist^i.- 

''J  gaisbeiQ  aiinoiilsO  boh  doJeoll 

.       .o')  yniybsid  BirnoiiljjiJ  him  ii6Iet>9 

•oO  noilBiolqxa  b(ia  gni^b^iid  bloO  sllivdiO 

..••  (...Mf-,.>t.,v:^  biiu  T^oiabaxfl  blo-DaHivfitO 

.o!J  j(iii3b9iG  bioO  deiJon  ^/'' ' 

'/>  ^m»ibeia  Wof>.»*ioa 

,  .   .    -I .?  >  sniabiia  oidq  la, 

!f9^:He;i  .11  .«Bl 


.  abJ-H"?  bloO  b9l«biIoii^U  adii 
>■:  fi)ii<Molqxa  i9viH  iBsa 

itiiirilnv.'tl   -KiviiT  •caafl 


THIS   BOOK    IS    DUE   ON    THE    LAST    DATE 
STAMPED   BELOW 


AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN  THIS  BOOK 
ON  THE  DATE  DUE.  THE  PENALTY  WILL  INCREASE  TO 
50  CENTS  ON  THE  FOURTH  DAY  AND  TO  $1.00  ON  THE 
SEVENTH  DAY  OVERDUE. 


,  I  ^^m^\ 


JAN  4    1973 


JUN  Sn  1980 
RECEfVED 

PHYS  SCI  LIBRARY 

JAN  0  6  1988 


in  198 


IB 


SEP -^0  1991 
^■^'  1391  Ktf  I 

r?ECEiv 

SFpT^3| 


Book  alip-20w-7,'56(C76Us4)458 


Cjaulci-a  z== 

PAMPHLET  BINDER 

'■  Syrocuse,  N.  Y. 

:      =    Stockton,  Colif. 


natural  resources, 
vision  of  mnes. 


PHYSICM. 
SCIENCES 
UBRARY 


Di- 


3   1175  00488  2422 

Call  Number: 

T112U 
C3 
A3 
no.  36 


no.  3(o 


LIBRAKT 

ui^IVERSITY  OF  CAI-U'Q?1™ 

DAVTC 


164901 


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